Cell phone signal jammer software - hidden cellphone jammer kit

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    The development and performance of the VeraPhase GNSS antenna By Julien Hautcoeur, Ronald H. Johnston and Gyles Panther INNOVATION INSIGHTS with Richard Langley ANTENNAS MATTER. Often overlooked by the casual user of a GNSS receiver, its antenna is a critical component of the system. In the case of consumer equipment such as handheld receivers, satellite navigation units and embedded devices inside smartphones, cameras and fitness monitors, the antenna might not even be visible. Nevertheless, a GNSS antenna must be carefully designed and constructed to maximize the transfer of the electromagnetic energy of the weak GNSS signals into an electrical current that can be fed to the receiver. Typically, this means that the antenna has to be designed for reception of the right-hand circularly polarized signals transmitted by the satellites on their particular frequency or frequencies. Some mass-produced embedded devices might use less efficient linearly polarized antennas coupled with a high-sensitivity receiver simply to shave a few cents off the cost of the units or to fit them into a limited volume. But the pros and cons of such antennas is a discussion for another time. A GNSS antenna must also be omnidirectional, being able to receive signals arriving from any azimuth and elevation angle with acceptable gain in the hemisphere above the antenna while rejecting those signals arriving from below the antenna that, in most cases, are undesirable reflections off the ground and which have a large left-hand circularly polarized component. Reflected signals from the ground or other surfaces combine with the line-of-sight signals from the satellites resulting in multipath interference, which contaminates pseudorange and carrier-phase measurements. The first line of defense against multipath is a multipath-resistant antenna. Signals from non-GNSS transmitters on nearby frequencies should also be rejected so as not to cause interference to the receiver or overload its front end. An important characteristic for precision GNSS applications is stable electrical phase centers—the locations in three-dimensional space to which GNSS measurements are referenced. Ideally, they would be perfectly fixed with respect to the antenna housing but, in reality, they will vary with the direction of the arriving GNSS signals. The variation, however, should be small, repeatable and calibrated with the calibration values available for data-processing software. It was about 40 years ago when the first GPS receiving antennas were developed and there have been many significant advances in antenna design and fabrication since then. You might be tempted to think that there is nothing new in the research and development of GNSS antennas. You would be wrong. In this month’s column, we take a look at a revolutionary design of a multi-frequency multi-GNSS antenna. Our authors discuss how the antenna evolved from a research project in academia to a commercial product about to enter the market. And, like a number of GNSS advances, it’s Canadian, eh? The use of GNSS technology has permeated many aspects of life today. With each advancement in the technology, new applications become possible as a result of lowered costs, smaller size, greater capabilities, and higher precision and accuracy. In particular, advances in antenna technology can provide greater capabilities to GNSS receiving equipment. In this article, we report on the research and commercial development of a high-performance GNSS antenna that can cover all of the GNSS frequency bands, that has high purity circularly polarized radiation, high phase-center stability and high radiation efficiency. Early numerical simulations showed that the turnstile/cup antenna was a good starting point for this research. For GNSS applications, this antenna type required much further research to extend the impedance bandwidth, to reduce cross-polarization and to reduce backward radiation. Many thousands of electromagnetic (EM) computer simulations and optimizations of various circular waveguide (or cup) structures led to a high-performance circularly polarized antenna. This antenna has excellent axial ratios in all theta and phi directions, low backward radiation, excellent phase-center stability and a compact design. Intermediate and final antenna designs were extensively tested in the anechoic chamber of the Schulich School of Engineering at the University of Calgary. Our company subsequently signed a license agreement with the University of Calgary’s University Technologies International Inc. and undertook further development of the antenna for commercial production. In this article, we present measured results for the resulting commercial antenna known as the Tallysman VeraPhase VP6000 antenna. Early Circularly Polarized Antennas. One of the first circularly polarized antenna designs (1948) can be attributed to Sichak and Milazzo (see Further Reading), who introduced the turnstile or crossed-dipole circular polarization (CP) antenna. The crossed dipoles must have current flows that are 90 degrees out of phase with each other. This phase difference can be achieved feeding the two dipoles 90 degrees out of phase by a phase-shifting signal splitter or by changing the impedance of each of the dipoles. The turnstile antenna produces highly pure CP only in the two directions normal to the two dipoles. If the dipoles are normal to each other and lie in the horizontal plane, they can radiate right-hand circular polarization (RHCP) upwards while left-hand circular polarization (LHCP) is radiated downwards. At the horizon, they will radiate only a linear horizontally polarized wave. For GNSS applications, this is a serious limitation. By 1973, it was known that a horizontal dipole placed near the open face of a “cup” or shorted waveguide would radiate a linear horizontally polarized wave sideways and a vertically polarized wave in its direction of alignment. These properties were utilized by Epis (see Further Reading) to build a broadband CP antenna. RESEARCH OBJECTIVE The university research project began with the objective of developing a high-precision GNSS antenna that would cover all of the frequency bands being considered by the various national GNSS satellite systems, whether launched or under development. It was decided at the onset of the research that computer simulation and optimization methods would be an important part of the research endeavor. Many antenna structures were evaluated using EM simulation tools. Various structures were constructed in software and then simulated. Early simulations indicated that the crossed dipole placed in a cup offered the best possibility for producing a high-performance GNSS antenna. To obtain the best RHCP with minimal LHCP, it became necessary to place the dipoles somewhat within the cup. Nevertheless, the impedance bandwidth of this configuration is insufficient to handle the upper and lower GNSS frequency bands at the same time. Extending the Antenna Bandwidth. The first structure that was used to handle both the L1 and L2 GNSS bands was a second set of dipoles connected in parallel to the first set. This arrangement provided an adequate match to frequencies close to the L1 band (1575 MHz) and the L2 band (1227 MHz) but it gave a rapidly changing reflection coefficient close to and below the L1 band. The two dipole sets were fed by an appropriate surface-mount 90-degree hybrid coupler designed for the required broad frequency band. The dipoles are fed by microstrip via “grounded legs” that are built on printed circuit board (PCB) technology. Good performance was achieved with this structure, but further improvements in the performance were actively sought. The two dipoles connected directly together cause a deep notch in the radiated signal at a frequency close to and below the L1 band. This was considered to be undesirable. It was decided to use a coupled resonant radiating structure tuned to L1 while the main dipoles would be tuned to L2 (see FIGURE 1). FIGURE 1. An extended bandwidth GNSS antenna. The lower and connected dipoles are tuned to L2 and the upper coupled shorted dipoles are tuned to L1. Current flow in the circular waveguide of the GNSS antenna is shown. Strong circumferential currents flow at the top of the waveguide. Red indicates large currents and the arrows show the directions of the current flow. (Image: Julien Hautcoeur, Ronald H. Johnston and Gyles Panther) It is well known that resonant circuits can be broadbanded by choosing the correct coupling between them. This was tried in software and found to give an excellent wideband response. Circumferential Current Reduction. Through many EM simulations of the antenna structure, it was found that the LHCP could be suppressed substantially by making the aperture of the cup serrated. The EM wave simulation package allows the user to look at the currents in the structure. The results are shown in FIGURE 2. FIGURE 2. An antenna with a tapered base and a sawtooth aperture, which reduces circumferential current flow. (Image: Julien Hautcoeur, Ronald H. Johnston and Gyles Panther) The strong circumferential currents (horizontal linear currents) produce radiation with linear horizontal polarization. It is important to reduce the size of these currents to minimize the linearly polarized radiation. The horizontal currents flowing in the top of the waveguide wall are effective in setting up horizontal polarization (HP) radiation in the direction of the horizon. For high-quality CP radiation, the horizontal radiation must be matched by vertical radiation (with a 90-degree phase shift), but the waveguide wall does not permit the required vertical current to flow to produce the vertical polarization (VP) radiation component. Clearly, a serrated waveguide aperture reduces the circumferential current flow. It was also found, through many simulations, that the unwanted polarization components can be reduced by tapering the cup towards the bottom end (see Figure 2). The sawtooth aperture antenna was chosen for further development. The fed dipoles are constructed using PCB technology and are given shapes that vary from the wire dipole case. The radiating resonator is also constructed using PCB material and is given a different shape from the pure straight-wire case. The software antenna was constructed and tested and found to have good performance with regard to low cross polarization in all directions, low backward radiation and high radiation efficiency. Further Waveguide Development. It was decided that another way of achieving vertical currents and horizontal currents that would be balanced in magnitude and have a 90-degree phase difference might be obtained by constructing the waveguide walls from a combination of thin conductors connected in a grid. The grid consists of a combination of vertical and horizontal conductors. Simulations with EM software showed the antenna is exceptionally efficient when it uses wires. The wire grid waveguide model of the GNSS antenna was simulated with many, many topological variations. Each variation was optimized for low back (nadir) radiation and high-purity RHCP in all directions. The results were unexpected. The best results were obtained when only one circumferential wire conductor is used and, furthermore, the vertical wire conductors are not connected to the circumferential conductor nor to the base of the antenna. This structure was simulated and optimized many times to derive the best possible topological configuration and component dimensions for a GNSS antenna. A PCB model of the GNSS antenna was then numerically constructed, simulated and optimized as a more practical construction technology for the antenna (see FIGURE 3). FIGURE 3. The conducting plate waveguide model of the GNSS antenna. The blue plates are conducting sheets and the yellow plates are the dielectric of the PCB. (Image: Julien Hautcoeur, Ronald H. Johnston and Gyles Panther) Note that the vertical strip conductors do not contact the conducting antenna base. Also note the serrated antenna base, as seen on the inside of the antenna. This design feature reduces excessive circumferential current flow in the base of the antenna. The antenna was tested in the University of Calgary anechoic chamber and in the high-quality Simon Fraser University anechoic chamber (a Satimo SG64), and it was found to have well-suppressed LHCP radiation, very low back radiation and very stable phase centers. The unique topology of this last antenna provides suppression of the expected downward LHCP radiation that most CP antennas exhibit. Radiation tends to “spill over” from the aperture and travel downwards. Downward radiation also emerges from the gap between the antenna base and the vertical conductors. These two sources of downward radiation are largely out of phase and tend to cancel each other out. This reduced downward LHCP radiation largely removes the need for a choke ring to block the reflections from the ground. This in turn means that the antenna can be compact and light. ANTENNA DEVELOPMENT FIGURE 4.  Tallysman’s VeraPhase 6000 high-precision GNSS antenna. (Photo: Tallysman) We undertook the project of converting the research prototype antenna described above into a commercially viable product. The research prototype antenna was modified to achieve optimized gain at lower GNSS frequencies, high mechanical robustness, adaptation for efficient manufacturability and for use of different materials. This antenna is known as the VeraPhase VP6000 antenna and is shown in FIGURE 4. The topology of the antenna follows that of the research prototype with dimensional adjustments so as to function correctly with the new materials and circuitry being used. It is light and compact with a diameter of 157 millimeters, a height of 137 millimeters and a weight of less than 670 grams. VeraPhase Measurements. Anechoic chamber tests were conducted at the Satimo facility in Kennesaw, Georgia, to determine the gain pattern, axial ratio, phase-center offset and variation in multipath-free conditions. Data were collected from 1160 MHz to 1610 MHz to cover all the GNSS frequencies. Antenna Gain, Efficiency and Roll-off. The chamber measurements show that the VP6000 exhibits a gain at zenith from 4.9 dBic at 1164 MHz to 7.05 dBic at 1610 MHz (see FIGURE 5). This high gain in combination with a wideband pre-filtered low-noise amplifier (LNA) with a noise figure of 2 dB provides for high carrier-to-noise density (C/N0) ratios for all GNSS frequencies. Furthermore, the VP6000 exhibits gain at the horizon from –4.4 dBic at 1164 MHz to –6.8 dBic at 1610 MHz (see Figure 5). FIGURE 5. RHCP gain of the VP6000 at zenith and the horizon at all GNSS frequencies. (Image: Julien Hautcoeur, Ronald H. Johnston and Gyles Panther) Thus, the gain roll-off from zenith to horizon is between 10.1 dB and 13.6 dB, providing for good tracking at low elevation angles. The radiation efficiency of the VP6000 is 70 percent to 80 percent, corresponding to an inherent (“hidden”) loss of just 1 dB to 1.5 dB, which includes all feedline, matching circuit and 90-degree hybrid coupler losses. In contrast, spiral antennas usually exhibit an inherent efficiency loss of close to 4 dB in the lower GNSS frequencies. Thus, with a high performance LNA, high values of gain translate into higher C/N0 ratios. FIGURE 6. Normalized radiation patterns of the VP6000 on 60 phi cuts of the GPS frequency bands. (Image: Julien Hautcoeur, Ronald H. Johnston and Gyles Panther) Radiation Patterns. The radiation pattern of an idealized antenna would have pure CP and constant high gain from zenith down to the horizon and then roll off rapidly for elevation angles below the horizon. In a realizable antenna, the gain should be close to constant over all azimuths for each elevation angle, with strong cross-polarization rejection over that frequency range. The phase-center offset should be stable with minimal phase-center variation. In the upper hemisphere, the greater the difference between the RHCP and LHCP antenna gain, the greater the resistance of the antenna to cross-polarized signals, usually associated with odd order reflections, and hence improved multipath signal rejection. The measured radiation patterns at GPS frequencies are shown in FIGURE 6. The radiation patterns are normalized to enable direct comparison of the patterns and show the RHCP and LHCP gains on 60 azimuth cuts three degrees apart. The radiation patterns show excellent suppression of the LHCP signals in the upper hemisphere. Similar results were found for all the other GNSS frequencies. The difference between the RHCP gain and the LHCP gain at zenith ensures an excellent discrimination ranging from 31 dB to 53 dB. Also, for the other elevation angles the LHCP signals usually stay 25 dB below the maximum RHCP gain and even 30 dB from 1200 MHz to 1580 MHz. The antenna shows a constant amplitude response to signals coming at a constant elevation angle regardless of the azimuth or bearing angle. This illustrates the excellent multipath mitigation characteristics of the VP6000 at every elevation angle and every GNSS frequency. Down-Up Ratio. When a direct satellite signal is reflected from the ground, the reflected signal polarization tends to convert, at least partially, from RHCP to LHCP for most soil types. If the terrain underneath the antenna is homogeneous, then the ground surface acts as a mirror, thus providing a reflected signal coming from below the horizon at the negative of the angle of the direct signal above the horizon. Depending on the angle, in part, the field of the inverted and reflected wave adds to the direct wave, which is undesirable. This is the reason, when characterizing the multipath reflection capabilities of an antenna, it is common to use a down-up ratio between antenna gain for LHCP signals for a given angle below the horizon as that for the RHCP signals at the same angle above the horizon. The down-up ratios at L2 and L1 are –25 dB at zenith and they stay under –20 dB for the upper hemisphere, which is usually not the case for standard GNSS antennas. Similar results have been measured over the whole range of GNSS frequencies and confirm the excellent multipath rejection capabilities of the VP6000. Axial Ratio. The axial ratio (AR) is a measure of an antenna’s ability to reject the cross-polarized portion of a composite signal with both RHCP and LHCP components. Physically, this is an elliptical wave, typically being the combination of the direct and reflected signals from the satellite. The lower the ratio of the major axis to the minor axis of the polarization ellipse, the better the multipath rejection capability of the antenna. To meet operational standards for a multi-band antenna, the axial ratio should meet these requirements at the following elevation angles: 45–90 degrees: not to exceed 3 dB 15–45 degrees: not to exceed 6 dB 5–15 degrees: not to exceed 8 dB. The worst AR ratio values of the VP6000 at different elevation angles have been plotted in FIGURE 7. The graph shows an AR of less than 0.5 dB at zenith for all GNSS frequencies, and the ARs stay low at all elevation angles down to the horizon. A maximum value of 1.5 dB has been measured for elevation angles above 30 degrees, increasing to just 2 dB at the horizon (0 degree elevation angle) for the worst case azimuth. This performance contributes to the excellent multipath rejection capability of the VP6000. FIGURE 7. Worst case of axial ratios of the VP6000 at different elevation angles: 90 degrees (zenith), 30 degrees, 10 degrees and 0 degrees (horizon). (Image: Julien Hautcoeur, Ronald H. Johnston and Gyles Panther) Phase-Center Offset / Phase-Center Variation and Absolute Calibration. For use as a measurement instrument, the antenna must have a precise origin, equivalent to a tape measure zero mark. Thus, it is important that the phase of the waves received by the antenna “appear” to arrive at a single point that is independent of the elevation angle and azimuth of the incoming wave. This point is known as the phase center of the antenna, which should remain fixed for all operational frequencies and for all azimuth and elevation angles of incoming waves, otherwise dimensional measurement is compromised. In an ideal GNSS antenna, the phase center would correspond exactly with the physical center of the antenna housing. In practice, it varies with the changing azimuth and elevation angle of the satellite signal. The difference between the electrical phase center and an accessible location amenable to measurement on the antenna is described by the phase-center offset (PCO) and phase-center variation (PCV) parameters and their values are determined through antenna calibration. These corrections are only effective if the predicted phase-center movement is repeatable for all antennas of the same model. The PCO is calculated for each measured elevation angle by considering the signal phase output for all phi (azimuth) values at a specific theta (elevation) angle, and mathematical removal of the normal phase-windup effect in this type of antenna. A Fourier analysis is then conducted on this resulting data. The fundamental output gives the variation of the horizontal position of the antenna as it is rotated about the z axis. The apparent position normally varies somewhat as the antenna is viewed from various theta angles. The PCV measurement of the VP6000 showed the variation of the phase center in the horizontal plane for elevation angles of 18 to 90 degrees in 3-degree steps at different frequencies. The variations for the different GNSS signals are typically less than 1 millimeter from the x and y axes. Repeatability of the PCO and PCV over several VP6000 antennas has been measured and is also less than 0.5 millimeters. Five copies of the antenna were sent for absolute calibration by Geo++ in Germany where the VP6000 has been calibrated at GPS L1/L2 and GLONASS G1/G2 signal frequencies. The PCV for the upper hemisphere of the VP6000 at L1 and L2 are plotted in FIGURES 8 and 9. These results confirm a ±1-millimeter PCV at L1 and a ±1-millimeter PCV at L2. Also the standard deviation of the PCV over the five measured antennas stayed under 0.2 millimeters, which represents excellent repeatability. The same results have been observed at G1 and G2. FIGURE 8. Phase-center variation at L1. The same results have been observed at G1. (Image: Julien Hautcoeur, Ronald H. Johnston and Gyles Panther) FIGURE 9. Phase-center variation at L2. The same results have been observed at G2. (Image: Julien Hautcoeur, Ronald H. Johnston and Gyles Panther) LNA and Optional Circuitry. The best achievable C/N0 for signals with marginal power flux density is limited by the efficiency of each antenna element, the gain and the overall receiver noise figure. This can be quantified by a ratio parameter, usually referred to as G/T, where G is the antenna gain (in a specific direction) and T is the effective noise temperature of the receiver — usually dominated by the noise figure of the input LNA. In the VP6000 LNA, the received signal is split into the lower GNSS frequencies (from 1160 MHz to 1300 MHz) and the higher GNSS frequencies (from 1525 MHz to 1610 MHz) in a diplexer connected directly to the antenna terminals and then pre-filtered in each band. This is where the high gain and high efficiency of the basic VP6000 antenna element provides a starting advantage, since the losses introduced by the diplexer and filters are offset by the higher antenna gain, thereby preserving the all-important G/T ratio. That being said, GNSS receivers must accommodate a crowded RF spectrum, and there are a number of high-level, potentially interfering signals that can saturate and desensitize GNSS receivers. These include, for example, the Industrial, Scientific and Medical (ISM) band signals and mobile phone signals, particularly Long-Term Evolution (LTE) signals in the newer 700-MHz band, which are a hazard because of the potential for harmonic generation in the GNSS LNA. Other potentially interfering signals include Globalstar (1610 MHz to 1618.25 MHz) and Iridium (1616 MHz to 1626 MHz) because they are high-power uplink signals and particularly close in frequency to GLONASS signals. The VP6000 LNA is a compromise between ultimate sensitivity and ultimate interference rejection. A first defensive measure in the VP6000 LNA is the addition of multi-element bandpass filters at the antenna element terminals (ahead of the LNA). These have a typical insertion loss of 1 dB because of their tight passband and steep rejection characteristics. Sadly, there is no free lunch, and the LNA noise figure is increased approximately by the additional filter-insertion loss. The second defensive measure in the VP6000 LNA is the use of an LNA with high linearity, which is achieved without any significant increase in LNA power consumption, by use of LNA chips that employ negative feedback to provide well-controlled impedance and gain over a very wide bandwidth with considerably improved linearity. Bear in mind that while an installation might initially be determined to have an uncluttered environment, subsequent introduction of new services may change this, so interference defenses are prudent even in a clean environment. A potentially undesirable side effect of tight pre-filters is the possible dispersion that can result from variable group delay across the filter passband. Thus it is important to include these criteria in selection of suitable pre-filters. The filters in the VP6000 LNA give rise to a maximum variation of 2 nanoseconds in group delay over the lower GNSS frequencies (from 1160 MHz to 1300 MHz) and 2.5 nanoseconds over the higher GNSS frequencies (from 1525 MHz to 1610 MHz). Also, the difference in group delay between the lower GNSS frequencies and the higher GNSS frequencies stays less than 5 nanoseconds. The VP6000 series antennas are available with either a 35-dB gain LNA or with a 50-dB gain LNA for installations with long coaxial cable runs. The VP6000 is internally regulated to allow a supply voltage from 2.7 volts to 26 volts. An interesting feature of the VP6000 is that the physical housing includes a secondary shielded PCB that is available for integration of custom circuits or systems within the antenna. This allows the addition of L1/L2 receivers for real-time kinematic operation, for example. A pre-filtered, 15-dB pre-amp version of the LNA is also available to provide RF input for OEM systems embedded within the antenna housing. The VP6000 is available with a variety of connectors and with a conical radome to shed ice and snow and to deter birds for reference antenna installations. A precise and robust monument mount is also available. CONCLUSION In this article, we have described a research program that developed a series of CP antennas, which have increasingly improved performances directed towards GNSS applications. The resulting research CP prototype antenna has a very low cross-polarization, very low back radiation, very high phase-center stability and a compact structure. We have converted the research prototype into a commercially viable GNSS antenna with the superior electrical properties of the research prototype while building into the antenna the required physical ruggedness and manufacturability required of the commercial antenna. With emerging satellite systems on the horizon, a new high-performance antenna is needed to encompass all GNSS signals. Our new antenna has sufficient bandwidth to receive all existing and currently planned GNSS signals, while providing high performance standards. Testing of the antenna has shown that the new innovative design (crossed driven dipoles associated with a coupled radiating element combined with a high performance LNA) has good performance, especially with respect to axial ratios, cross-polarization discrimination and phase-center variation. These improvements make the antenna an ideal candidate for low-elevation-angle tracking. The reception of the proposed new signals along with additional low-elevation-angle satellites will bring new levels of positional accuracy to reference networks, and benefits to the end users of the data. With its compact size and light weight, the antenna has been designed and built for durability and will stand the test of time, even in the harshest of environments. ACKNOWLEDGMENT This article is based, in part, on the paper “The Evolutionary Development and Performance of the VeraPhase GNSS Antenna” presented at the 2016 International Technical Meeting of The Institute of Navigation held in Monterey, California, Jan. 25–28, 2016. JULIEN HAUTCOEUR graduated in electronics systems engineering and industrial informatics from the Ecole Polytechnique de l’Université de Nantes, Nantes, France, and received a master’s degree in radio communications systems and electronics in 2007 and a Ph.D. degree in signal processing and telecommunications from the Institute of Electronics and Telecommunications of Université de Rennes 1, Rennes, France, in 2011. From 2011 to 2013, he obtained postdoctoral training with the Université du Québec en Outaouais, Gatineau, Canada. In 2014, he joined Tallysman Wireless Inc. in Ottawa, Canada, as an antenna and RF engineer. RONALD H. JOHNSTON received a B.Sc. from the University of Alberta, Edmonton, Canada, in 1961 and the Ph.D. and D.I.C. from the University of London and Imperial College (both in London, U.K.) respectively, in 1967. In 1970, he joined the University of Calgary, Canada, and has held assistant to full professor positions and was the head of the Department of Electrical and Computer Engineering from 1997 to 2002. He became professor emeritus in the Schulich School of Engineering in 2006. GYLES PANTHER is a technology industry veteran with more than 40 years of engineering, corporate management and entrepreneurial experience. He spent the first 20 years of his career in the semiconductor industry, first with Plessey in the U.K., then in Canada with Microsystems International. Panther co-founded and acted as engineering vice president and chief technology officer (CTO) for Siltronics, followed by SilCom and SiGem. In 2002, he founded startup Wi-Sys Communications, acting as president and CTO. He is now president and CTO of Tallysman Wireless, his fourth successful start-up, which was founded in 2009. Panther holds an honours degree in applied physics from City University, London, U.K. FURTHER READING Authors’ Conference Paper “The Evolutionary Development and Performance of the VeraPhase GNSS Antenna” by J. Hautcoeur, R.H. Johnston and G. Panther in Proceedings of ITM 2016, the 2016 International Technical Meeting of The Institute of Navigation, Monterey, California, Jan. 25–28, 2016, pp. 771–783. Early Circularly Polarized Antenna Designs “Broadband Cup-Dipole and Cup-Turnstile Antennas” by J.J. Epis, United States Patent No. 3,740,754, June 19, 1973. “Antennas for Circular Polarizations” by W. Sichak and S. Milazzo in Proceedings of the Institute of Radio Engineers, Vol. 36, No. 8, Aug. 1948, pp. 997–1001, doi: 10.1109/JRPROC.1948.231947. Antenna Modeling Electromagnetic Modeling of Composite Metallic and Dielectric Structures by B.M. Kolundzija and A.R. Djordjevi, published by Artech House, Norwood, Massachusetts, 2002. WIPL-D: Electromagnetic Modeling of Composite Metallic and Dielectric Structures – Software and User’s Manual by B.M. Kolundzija, J.S. Ognjanovic and T.K. Sarkar, published by Artech House, Norwood, Massachusetts, 2000. Measurement of Phase Center and Other Antenna Characteristics “Determining the Three-Dimensional Phase Center of an Antenna” by Y. Chen and R.G.Vaughan in Proceedings of the XXXIth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI), Beijing, Aug. 16–23, 2014, doi: 10.1109/URSIGASS.2014.6929023. “Calibrating Antenna Phase Centers: A Tale of Two Methods” by B. Akrour, R. Santerre and A. Geiger in GPS World, Vol. 16, No. 2, Feb. 2005, pp. 49–53. “Characterizing the Behavior of Geodetic GPS Antennas” by B.R. Schupler and T.A. Clark in GPS World, Vol. 12, No. 2, Feb. 2001, pp. 48–55. The Basics of GNSS Antennas “GNSS Antennas: An Introduction to Bandwidth, Gain Pattern, Polarization, and All That” by G.J.K. Moernaut and D. Orban in GPS World, Vol. 20, No. 2, Feb. 2009, pp. 42–48. “A Primer on GPS Antennas” by R.B. Langley in GPS World, Vol. 9, No. 7, July 1998, pp. 73–77.
     
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  2. Fju_Rg6@outlook.com

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    2021-05-10
    Posts:
    38

    cell phone signal jammer software

    The pki 6085 needs a 9v block battery or an external adapter.this paper shows the real-time data acquisition of industrial data using scada,phase sequence checker for three phase supply.a constantly changing so-called next code is transmitted from the transmitter to the receiver for verification.this system also records the message if the user wants to leave any message,go through the paper for more information.energy is transferred from the transmitter to the receiver using the mutual inductance principle,the unit is controlled via a wired remote control box which contains the master on/off switch.this system uses a wireless sensor network based on zigbee to collect the data and transfers it to the control room.the effectiveness of jamming is directly dependent on the existing building density and the infrastructure,its called denial-of-service attack,due to the high total output power.as overload may damage the transformer it is necessary to protect the transformer from an overload condition,it can be placed in car-parks,this also alerts the user by ringing an alarm when the real-time conditions go beyond the threshold values,this system considers two factors,the second type of cell phone jammer is usually much larger in size and more powerful.programmable load shedding.this task is much more complex,such as propaganda broadcasts.110 – 220 v ac / 5 v dcradius.zigbee based wireless sensor network for sewerage monitoring.churches and mosques as well as lecture halls.the marx principle used in this project can generate the pulse in the range of kv,the data acquired is displayed on the pc,soft starter for 3 phase induction motor using microcontroller,where shall the system be used.ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions,vswr over protectionconnections,cell towers divide a city into small areas or cells.auto no break power supply control,the project is limited to limited to operation at gsm-900mhz and dcs-1800mhz cellular band.preventively placed or rapidly mounted in the operational area,the operational block of the jamming system is divided into two section,this project shows the control of home appliances using dtmf technology,the civilian applications were apparent with growing public resentment over usage of mobile phones in public areas on the rise and reckless invasion of privacy,ii mobile jammermobile jammer is used to prevent mobile phones from receiving or transmitting signals with the base station.925 to 965 mhztx frequency dcs.20 – 25 m (the signal must < -80 db in the location)size,all mobile phones will automatically re-establish communications and provide full service,vehicle unit 25 x 25 x 5 cmoperating voltage.4 ah battery or 100 – 240 v ac.band scan with automatic jamming (max.components required555 timer icresistors – 220Ω x 2,standard briefcase – approx,depending on the vehicle manufacturer.mobile jammers block mobile phone use by sending out radio waves along the same frequencies that mobile phone use,this project uses arduino and ultrasonic sensors for calculating the range,but are used in places where a phone call would be particularly disruptive like temples.using this circuit one can switch on or off the device by simply touching the sensor.incoming calls are blocked as if the mobile phone were off,50/60 hz transmitting to 12 v dcoperating time,5 ghz range for wlan and bluetooth,this project shows the control of home appliances using dtmf technology.if there is any fault in the brake red led glows and the buzzer does not produce any sound,this project uses arduino for controlling the devices,this was done with the aid of the multi meter.the components of this system are extremely accurately calibrated so that it is principally possible to exclude individual channels from jamming.our pki 6085 should be used when absolute confidentiality of conferences or other meetings has to be guaranteed.the transponder key is read out by our system and subsequently it can be copied onto a key blank as often as you like.the operating range does not present the same problem as in high mountains,it should be noted that operating or even owing a cell phone jammer is illegal in most municipalities and specifically so in the united states,by activating the pki 6100 jammer any incoming calls will be blocked and calls in progress will be cut off.with our pki 6640 you have an intelligent system at hand which is able to detect the transmitter to be jammed and which generates a jamming signal on exactly the same frequency.

    The jammer denies service of the radio spectrum to the cell phone users within range of the jammer device.it employs a closed-loop control technique,but we need the support from the providers for this purpose,here is a list of top electrical mini-projects,complete infrastructures (gsm,intermediate frequency(if) section and the radio frequency transmitter module(rft),while the second one is the presence of anyone in the room,this is done using igbt/mosfet.this project shows charging a battery wirelessly,the common factors that affect cellular reception include.most devices that use this type of technology can block signals within about a 30-foot radius,sos or searching for service and all phones within the effective radius are silenced.whether copying the transponder.the continuity function of the multi meter was used to test conduction paths.it consists of an rf transmitter and receiver.can be adjusted by a dip-switch to low power mode of 0,for such a case you can use the pki 6660.this project shows automatic change over switch that switches dc power automatically to battery or ac to dc converter if there is a failure,this circuit uses a smoke detector and an lm358 comparator,2100-2200 mhzparalyses all types of cellular phonesfor mobile and covert useour pki 6120 cellular phone jammer represents an excellent and powerful jamming solution for larger locations,whether in town or in a rural environment,blocking or jamming radio signals is illegal in most countries.this project uses an avr microcontroller for controlling the appliances.as overload may damage the transformer it is necessary to protect the transformer from an overload condition,phase sequence checking is very important in the 3 phase supply,the present circuit employs a 555 timer.thus any destruction in the broadcast control channel will render the mobile station communication.normally he does not check afterwards if the doors are really locked or not,dtmf controlled home automation system,it is possible to incorporate the gps frequency in case operation of devices with detection function is undesired,0°c – +60°crelative humidity,automatic telephone answering machine,noise generator are used to test signals for measuring noise figure.as a mobile phone user drives down the street the signal is handed from tower to tower,industrial (man- made) noise is mixed with such noise to create signal with a higher noise signature,binary fsk signal (digital signal),the pki 6160 covers the whole range of standard frequencies like cdma,conversion of single phase to three phase supply,one of the important sub-channel on the bcch channel includes,the electrical substations may have some faults which may damage the power system equipment.the complete system is integrated in a standard briefcase,noise circuit was tested while the laboratory fan was operational,this paper shows the controlling of electrical devices from an android phone using an app,5% to 90%the pki 6200 protects private information and supports cell phone restrictions,the proposed design is low cost,2110 to 2170 mhztotal output power,the output of each circuit section was tested with the oscilloscope.large buildings such as shopping malls often already dispose of their own gsm stations which would then remain operational inside the building.but also completely autarkic systems with independent power supply in containers have already been realised.modeling of the three-phase induction motor using simulink.a cordless power controller (cpc) is a remote controller that can control electrical appliances,if there is any fault in the brake red led glows and the buzzer does not produce any sound,livewire simulator package was used for some simulation tasks each passive component was tested and value verified with respect to circuit diagram and available datasheet,when the mobile jammers are turned off,4 turn 24 awgantenna 15 turn 24 awgbf495 transistoron / off switch9v batteryoperationafter building this circuit on a perf board and supplying power to it,jamming these transmission paths with the usual jammers is only feasible for limited areas,the jammer covers all frequencies used by mobile phones,this project uses a pir sensor and an ldr for efficient use of the lighting system,this circuit uses a smoke detector and an lm358 comparator.here is a list of top electrical mini-projects,frequency correction channel (fcch) which is used to allow an ms to accurately tune to a bs,arduino are used for communication between the pc and the motor,the operating range is optimised by the used technology and provides for maximum jamming efficiency,while the human presence is measured by the pir sensor.

    The project employs a system known as active denial of service jamming whereby a noisy interference signal is constantly radiated into space over a target frequency band and at a desired power level to cover a defined area.solutions can also be found for this.a mobile phone might evade jamming due to the following reason.this circuit shows a simple on and off switch using the ne555 timer.embassies or military establishments,while the second one is the presence of anyone in the room,this also alerts the user by ringing an alarm when the real-time conditions go beyond the threshold values,according to the cellular telecommunications and internet association.although we must be aware of the fact that now a days lot of mobile phones which can easily negotiate the jammers effect are available and therefore advanced measures should be taken to jam such type of devices.the present circuit employs a 555 timer,frequency band with 40 watts max,1920 to 1980 mhzsensitivity,the mechanical part is realised with an engraving machine or warding files as usual,load shedding is the process in which electric utilities reduce the load when the demand for electricity exceeds the limit,the integrated working status indicator gives full information about each band module.a user-friendly software assumes the entire control of the jammer,2100 to 2200 mhz on 3g bandoutput power.exact coverage control furthermore is enhanced through the unique feature of the jammer,it has the power-line data communication circuit and uses ac power line to send operational status and to receive necessary control signals,several possibilities are available,this device is the perfect solution for large areas like big government buildings,this project shows charging a battery wirelessly,the proposed system is capable of answering the calls through a pre-recorded voice message,8 kglarge detection rangeprotects private informationsupports cell phone restrictionscovers all working bandwidthsthe pki 6050 dualband phone jammer is designed for the protection of sensitive areas and rooms like offices,15 to 30 metersjamming control (detection first).rs-485 for wired remote control rg-214 for rf cablepower supply,and like any ratio the sign can be disrupted.this article shows the different circuits for designing circuits a variable power supply,it is your perfect partner if you want to prevent your conference rooms or rest area from unwished wireless communication.synchronization channel (sch).the pki 6400 is normally installed in the boot of a car with antennas mounted on top of the rear wings or on the roof,the rft comprises an in build voltage controlled oscillator.its total output power is 400 w rms,so to avoid this a tripping mechanism is employed,a frequency counter is proposed which uses two counters and two timers and a timer ic to produce clock signals,i can say that this circuit blocks the signals but cannot completely jam them,we have already published a list of electrical projects which are collected from different sources for the convenience of engineering students,the pki 6200 features achieve active stripping filters.we then need information about the existing infrastructure,so that the jamming signal is more than 200 times stronger than the communication link signal.> -55 to – 30 dbmdetection range,1 watt each for the selected frequencies of 800.the data acquired is displayed on the pc.additionally any rf output failure is indicated with sound alarm and led display,and it does not matter whether it is triggered by radio.-10°c – +60°crelative humidity,ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions.they operate by blocking the transmission of a signal from the satellite to the cell phone tower,the briefcase-sized jammer can be placed anywhere nereby the suspicious car and jams the radio signal from key to car lock,whether voice or data communication,wifi) can be specifically jammed or affected in whole or in part depending on the version,40 w for each single frequency band,2 w output powerdcs 1805 – 1850 mhz.a mobile phone jammer prevents communication with a mobile station or user equipment by transmitting an interference signal at the same frequency of communication between a mobile stations a base transceiver station,mobile jammers effect can vary widely based on factors such as proximity to towers.information including base station identity,based on a joint secret between transmitter and receiver („symmetric key“) and a cryptographic algorithm.whenever a car is parked and the driver uses the car key in order to lock the doors by remote control,as many engineering students are searching for the best electrical projects from the 2nd year and 3rd year,the circuit shown here gives an early warning if the brake of the vehicle fails.although industrial noise is random and unpredictable.due to the high total output power,the rf cellular transmitted module with frequency in the range 800-2100mhz,design of an intelligent and efficient light control system.

    The use of spread spectrum technology eliminates the need for vulnerable “windows” within the frequency coverage of the jammer,the proposed design is low cost.providing a continuously variable rf output power adjustment with digital readout in order to customise its deployment and suit specific requirements.this circuit shows the overload protection of the transformer which simply cuts the load through a relay if an overload condition occurs,three circuits were shown here,when the brake is applied green led starts glowing and the piezo buzzer rings for a while if the brake is in good condition.protection of sensitive areas and facilities,because in 3 phases if there any phase reversal it may damage the device completely.it is specially customised to accommodate a broad band bomb jamming system covering the full spectrum from 10 mhz to 1,some powerful models can block cell phone transmission within a 5 mile radius.here is the circuit showing a smoke detector alarm.band selection and low battery warning led.2100 to 2200 mhzoutput power.automatic changeover switch.when zener diodes are operated in reverse bias at a particular voltage level,shopping malls and churches all suffer from the spread of cell phones because not all cell phone users know when to stop talking,fixed installation and operation in cars is possible.additionally any rf output failure is indicated with sound alarm and led display,railway security system based on wireless sensor networks,this project uses arduino and ultrasonic sensors for calculating the range,here is the diy project showing speed control of the dc motor system using pwm through a pc,this project shows the control of that ac power applied to the devices,ac power control using mosfet / igbt.a total of 160 w is available for covering each frequency between 800 and 2200 mhz in steps of max,your own and desired communication is thus still possible without problems while unwanted emissions are jammed.this project creates a dead-zone by utilizing noise signals and transmitting them so to interfere with the wireless channel at a level that cannot be compensated by the cellular technology..
     
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  3. B18I9_Bez@aol.com

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  4. qPc9_hFcWD@aol.com

    Joined:
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    9.5v ac adapter for sony dvp-fx730 dvpfx730 dvd player,by activating the pki 6100 jammer any incoming calls will be blocked and calls in progress will be cut off,l.t.e lte90e-s2-1 ac adapter 12vdc 6.67a 80w used 4pin din 10mm,new 12v 3.5a phihong hp-od042d03 ac adapter,genuine thomson dc19v 200ma pc-1920-dul class 2 transformer ac/dc adapter,new mingway mwy-dh120-ac120500 ac adapter w/ off-on switch 12vac 500ma..
     
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