Genesys Resonant Active Tunable ***** GRAT – Antenna ***** February 2012 Introduction Since 2006 Genesys had been developing an antenna for specific use in RCIED jamming application. However, the new design of the antenna proved to have unique features and characteristic to allow vast potential and wide area of application: Line-of-sight communication devices for emergency services (police, ambulance, firefighters, etc), Vehicle-born hidden antennas system; The vehicle and ships intercom wireless network; Railway transport communication and security; Ships and boats communication; Aircraft-type antenna; Satellites, any types; Robotic Systems (remote control and data acquisition); Unmanned devices, Line-of-Sight local control; Missile delivered radio-beacon, repeater or RF jamming unit NOTE: Dimension directly depended on used frequency. This presentation is based on our design for the specific application of antenna. The sizes, dimensions, weight apply to this particular application and can easily be decreased for use in hand-held devices with no degradation to the feature set. Invention The Genesys LTD introduce new concept in RF antenna developing. Working model: Genesys Resonant Active Tunable (GRAT) Antenna The design concept: Small-sized, tunable wide-band loop-slot antenna. The general specifications of emission and receiving of our antenna close to classical quarter-wave antenna. The functionality of the antenna: transmitting/receiving, wideband tunable, narrow passband on tuned frequency, resonant, harmonicsuppressed antenna. The differences is in a very narrow passband and the possibility of fast tuning of the passband central frequency. The GRAT-antenna is a basic element and depending of application can be used as a single antenna or as the set of antennas for the variety of transmitting and receiving systems. Invention explanation The classical theory for the design of antenna systems considers the antenna as an open oscillatory circuit which is excited by an electrical signal. As the result, the antenna can either, accept external electromagnetic waves, or antenna circuit should generate an electrical signal for the emission of electromagnetic waves. For small-sized antennas, the optimum size is a half the length of the working wavelength. Meanwhile, there are many other approaches in the design of antennas for implementing missing features in an open resonant circuit type antennas. This group of antennas includes phased array antennas, fractal antennas, log periodic antennas, etc. In most cases, the linear dimensions of antenna equals to a quarter or half of the working wavelength, which relates to the basic principle of designing an antenna as an open oscillatory circuit. Known improvement of their parameters are mainly related to the possibility of adding directional selectivity or limiting the range of received frequencies. The features of the GRAT-antenna design give opportunity to replace whip antennas used in HF,VHF and UHF diapasons. Without losing all the positive properties of standard antennas, plus, the GRAT antenna has a wideband characteristic with a harmonic-suppression characteristic. the proposed GRAT antenna makes it possible to create an energy-efficient, barely visible, durable, antenna systems for radio communications task, RF monitoring and using with contemporary protecting RF devices. Major advantages: Size The dimensions of the GRAT-antenna directly relates to the wavelength of used bandwidth and can be easy calculated. The high is equal to the lower work frequency wavelength (λ) multiplying by 0.01, and length is equal to λ*0.1. Rod/Whip antenna height - 98.42“ (standard band 30 MHz to 89 MHz) GRAT-Antenna GRAT-Antenna height is just slightly more than the OEM roof rack. The profile of the vehicle almost does not change after installation. height length 3.19" 31.92“ (calculated for working frequency: 37 MHz) No long-whip antenna Benefits and examples of use GRAT Antenna can successfully replace the standard antennas used now: 4-foot long whips. Solved problem: No need to tie down long-whip antenna. This is usually done in urban environment to avoid impact between the long-whip antenna and hanging wires or other obstacles. When the long-whip antenna tied down or lowered it looses its workability. GRAT antenna newer strike electric wires, telephone cables, etc. GRAT Antenna has very low vertical profile Solved problem: GRAT antenna installed on the vehicle and when used as a part of jamming system allows better concealment comparing with long-whip antennas. GRAT Antenna: compact and rigid Solved problem: The long-whip antennas often can snip or break at the impact. In addition to being compact GRAT antenna can be manufactured to be rigid. This shall significantly lower necessity to troubleshoot, fix, replace antennas itself. GRAT Antenna: Portability The design of the antenna allows easy portability. Roofmounted design eliminates the need to install whip rods on vehicle’s bumper where it usually requires cables to be placed outside of the vehicle, requires special mounting provisions, gets in the way of doors, and thus makes antenna more prone to problems. Major references 1) 2) Q-factor Q 100; (Our latest experiments with new, next generation, antenna prototype give as an opportunity to expect quality factor increasing to Q 1000 ); f f The bandwidth of the antenna f max 0 0.01 f 0 (represents the difference, depending 0 f min Q on the quality factor, between the upper and lower limit frequencies of the antenna; 3) Availability of electronic tuning to the specified resonance frequency value ( f 0 ) (by varactor diodes or switched capacitors etc); 4) The coefficient of overlap in frequency K 0 C max 2...4 (where C represents max and min C min value of tuning capacitance), 5) The height of the antenna curtains h 0.02...0.01max ; 6) The length of the antenna curtains l 0.2...0.1max ; 7) Vertical polarization; 8) Omni-directional pattern (basic models); 9) Strong electric (E) and magnetic (H) fields increase the reactive near-field to no less than 0.5 which is larger than the near-field of classical antennas, as known as 0.15 ; Major advantages: Quality The classical Q-factor, defined as the quotient between the stored and radiated energies for our GRAT antenna is Q=100 Our latest experiments with new, next generation, antenna prototype give as an opportunity to expect quality factor increasing up to 1000 high performance decrease or eliminate unwanted and spurious emission Major advantages: Bandwidth The bandwidth of the antenna Δƒ depends on Q-factor and operating frequency range The bandwidth of the our antenna is 1%. The standard quarter-wave vertical antennas have a bandwidth of 20…200 times larger than our GRAT antenna. The active tuning mode allow overlap frequency range with coefficient K = 2…4 Allow to design protected, narrowband, multi channel communication devices with expanded “Frequency Hopping” capability. GRAT-Antenna allows to achieve several highly important goals pursued by the Battlefield Spectrum Management: It increases the maximum number of frequencies available in the area of operation and spreads the frequencies in the hopsets across the widest possible band to optimize Electronic Counter-Counter Measures (ECCM) capabilities. Spreading the frequencies across the spectrum is more important than increasing the total number of frequencies available. Major advantages: Power Strong electric (E) and magnetic (H) field increases the reactive near field to not less than 0.5λ that is more than the near field of classical antennas, equal, as is known, 0.15λ Control circuit allow reduce power consumption up to 80% in some applications Major advantages: Other •Narrow passband antenna with wide range tuning •Electronically or manually tuning •Flat gain over frequency range •Low vertical dimension of antenna •Circular radiation pattern (basic), or can be modified •Either, fixed frequency or scanning frequency operation mode •Improve receiver third-order intermodulation dynamic range •Improve receivers signal-noise, post processing, ratio •Active, sharp, cancellation of antennas posttransmitting oscillation •Possibility to create silent/active spot pattern in active frequency band. •Can be used as a standalone device •Can be mounted as a parts of the object of interest •Compatibility with SDR communication devices •SDR system hardware design simplification •Good replacement for rod/whip VHF antennas •In some cases, eliminates the need for RF amplifier for the transmitter •Decrease unwanted oscillation in transmitting mode •Increase sensitivity and selectivity of the receivers •Increase receivers interference immunity •EMC improvement SDR-based Radio systems The main concept of the Software-Defined Radio (SDR) radio is that the radio can be totally configured or defined by the software. In this case a common platform can be used across a number of areas and common software can be used to change the configuration of the radio for the function required at a given time. Launched with a Mission Needs Statement in 1997 and a subsequent requirements document in 1998, The Joint Tactical Radio System (JTRS) is planned to be the next-generation voice-and-data radio used by the US military in field operations after 2010. The JTRS is a Software-Defined Radio (SDR) that will work with many existing military and civilian radios. SDR allows to use single hardware platform and it can communicate using one of a variety of waveforms simply by reloading or reconfiguring the software for the particular application required. This is a particularly attractive aspect, especially for coalition style operations where forces from different countries may operate together. The radios can be re-configured to enable communications to occur between troops from different countries, etc. One of the basic goals underlying the construction of SDR systems is to maximize simplification of the structure and/or exclude analog components. Nevertheless, this simplification often reduces the efficiency of SDR systems. Particularly in conditions when powerful signals exist outside the band received frequencies. The reason for this is to ignore, in most cases, necessity to filter the desired signal before the first amplification stage, or signal conversion. However, adding the filters greatly complicates the technical implementation of the SDR system. As we proclaimed in a beginning, when the proposed antenna is parts of SDR system , the antenna play additional role of tunable receiver preselector, and easily controlled by settings of SDR system itself. RECEIVING MODE TRANSMITTING MODE SDR-based Radio systems IN RECEIVING MODE combination of SDR system and the proposed antenna will improve the following characteristics of the RF system: Improves the parameters of EMC by increased noise immunity Extends the receiver third order intermodulation dynamic range Increases the real sensitivity of antennareceiver system Increases input selectivity of the receiver Allow to exclude switchable analog filters from the SDR system Adds direct flexibility control over the antenna parameters from SDR system control software SDR-based Radio systems IN TRANSMITTING MODE combination of SDR system and the proposed antenna will improve the following characteristics of the RF system: Increases battery life or allows to reduce dimension and mass of the battery Rejects side-oscillations emitted by the transmitters (harmonics, sub-harmonics, intermodulation oscillations, the combination oscillations) ), thus eliminating the need to apply additional filters; Reduces levels of band noise oscillations beyond the antenna bandwidth Ability to combining the multiple transmiting antenna systems in one array for extending frequency coverage range Decreases the bilateral influence from simultaneously worked and nearby located transmitter, which also leads to a decreasing bilateral intermodulation oscillations; GRAT-Antenna: Solving essential problems in RF communications (1) VHF is a Line-of-Sight system: two stations can talk to each other assuming that they are tuned to the same frequency and they can "see" each other (from a radio point of view). If one of the station’s antennas is below the horizon of the other station communication becomes unstable or completely impossible. The situation becomes worse because of the spurious, unwanted emissions and intermodulation distortion consist in transmitted radio signals. Modern receiving and transmitting radio equipment usually has broadband transmit and receive channel. Current methods of quality matching the output stage of the transmitter to the antenna-feeder arrangement do not entirely resolve the problem. By reducing the spurious emissions of the radio transmitting devices we can reduce electromagnetic pollution of the atmosphere. In addition, the decline in spurious emissions actively lessens the utilization of the frequency bandwidth resource. Being tuned to the same frequency means that both stations are tuned to the same pre-defined frequency within the occupied band. These predefined frequencies are separated by agreed "spaces", (expressed in KHz.). The spaces ensure that communications taking place on adjacent pre-defined frequencies do not interfere with each other. If transmitted signal has high power emission level stations mast be separated by certain distance to prevent unwanted interferences and frequency overlapping. This is dictated by nature of physics of radio wave propagation and antennas wide passband. The need of such channels separation brings limitation of station density per covered area and difficulty to communication between network users or even make it impossible due cannels overload. When bands are crowded with strong signals, the ability to hear a weak signal a few KHz away from an exceptionally strong signal is what separates a decent receiver from a superior receiver. Such problems and many other can be solved with our antenna. Timeline of the problem Originally the spacing between the frequencies was set to 200 KHz, providing just 70 channels between 118-132 MHZ (band in 1947). In 1958, the spacing was reduced to 100 KHz, doubling the number of channels to 140. In 1959 the upper limit of the some band was expanded to 136 MHz, giving us another 40 channels, bringing the total to 180. In 1964, the channel spacing was halved again to 50 KHz, resulting in 360 channels being available. These dates show not only customer ever increasing hunger for frequencies, but also the evolution of radios itself. In the 1950s no radio set would have been suitable for work with 50 KHz spacing. By 1964, 50 KHz was the standard. The channel spacing was further cut to 25 KHz in 1972, doubling the available channels to 720. Seven years later, in 1979, the upper limit of the band was once again expanded, this time to 137 MHz and this delivered another 40 channels, bringing the total to 760. In 1995 Today, channel space is 12.5 KHz and the proposal was made to reduce the channel spacing to 6.25 kHz in year 2013. GRAT-Antenna: Solving essential problems in RF communications (2) The range of the system is largely determined by terrain and the power source of radio emission. The standard average value range in the open space is about 10 - 15 km for the 5W transmitter. The most unpleasant effect of blocking the receiver is very strong single signal lying outside the channel received and third-order intermodulation due to the proximity of the two strong signals, separated in frequency in the band are listening to radio (IMD3). The picture below represent emission spectrum of standard antenna during transmitting mode. Intermodulation, spurious and unwanted signals 1 - Channel bandwidth 2 -Unwanted emission 3 - Spurious emission 4 - Combination oscilation 5 - Harmonics emission 6 - Sub-harmonic frequency 7 - Out-of band signal emission 8 - Out-of-band noise emission Virtually all modern types of antennas are designed on the basis of general provision that for effective signal transmission and reception an antenna system shall have dimensions of about 1/2, 5/8 or a 1/4 wavelength. At the same time take into considerations that reception and transmission of information is done using narrowband signals, so the actual bandwidth of the antenna system may be equal to the width of the spectrum used in the work of the signals. In practice, this means that if we provide work on one frequency, it is necessary to implement an effective antenna system demonstrating selectivity at a given frequency and with the required bandwidth. Working in a wide range of frequencies dictates to use knowingly wideband antenna system. This requires additional arrangements to improve the parameters of the electromagnetic compatibility (EMC) of connected equipment in order to maintain equipment working capacity in case of arrival to the input of the receiver or transmitter output signals from external sources of interference or noise. GRAT-Antenna: Solving essential problems in RF communications (3) In the RF diapasons the effective sizes of antennas cannot be less than some critical size. As a consequence, we have to choose between optimal antenna parameters and the required dimensions of antennas. In course of last 10-15 years, the design of equipment for transmitting and receiving of radio signals moved to a new level, associated the widespread use of digital signal processing techniques. However, this does not eliminate the need for analog components and matching them with a digital signal processing components. Nevertheless, the concept of the Software Defined Radio (SDR) becomes more of a reality and after SDR cognitive radio (CR) technology will be the next major step forward to enable the development of more effective radio communications systems. Feature of these systems is tendency to reduce the use of analog signal processing units what may degrade performance of the whole system. The problem of conversion received wideband analog signal into a frequency range suitable for further conversion into a digital form is one reason to use such methods in the development of radio receivers . As a result, remain unexplored features and capabilities of the input stages of such a system in a wide range of frequencies and with different levels of signals that are present at the input of the radio system Now, in use already existed and also new devices in developing, for over-horizon communications at frequencies up to 30 MHz, and for line-of-sight communication at frequency range from 30 MHz to 500 MHz.Also known, the HF/VHF networks require special considerations in frequency assignments. The antenna tuning limits the range of frequencies allowed. The farther the frequencies are dispersed from the center or tuning frequency, the poorer the quality of the circuit. Some networks must use hopsets restricted to a narrow distribution of frequencies, and networks that are subject to high level jamming require maximum dispersion of frequencies in the hopset. The main drawback of wide dispersion of frequencies is poor system quality. The poor quality is due to lower radiated power from the antenna when the hops are on frequencies at the specified limits of the bands. GRAT-Antenna: Solving essential problem in RF communications (4) Regarding to the Combat Net Radio (CNR) Frequency Management, the Battled Spectrum Management assigns the maximum number of frequencies available in the area of operation and spreads the frequencies in the hopsets across the widest possible band to optimize Electronic Counter-CounterMeasures (ECCM) capabilities. Spreading the frequencies across the spectrum is more important than increasing the total number of frequencies available. Smaller number of frequencies distributed over a broadband range, better protected from the jamming devices, compared with a large number of frequency allocated for narrowband. Thus, the development and use of radio equipment to operate in this mode will continue. As a good example, is the Joint Tactical Radio System (JTRS). It is planned to be the next-generation voice-anddata radio used by the U.S. military in field operations after 2010. And, therefore, development and production of efficient small-sized radio communication systems that meet modern requirements remains actual. The properties of GRAT-antenna allow working in wideband range with different location of central frequency and narrow band pass if needed. GRAT-Antenna: Solving essential problems in RF communications (5) 1. Produces controlled Amplitude-Frequency-Phase noise signal in the frequency band equal to ∆ = 1% of the average frequency with emission depended on jammer power. 2. The antenna realize the benefits of ability to suppress specific source signals without disrupting other communication systems with different working frequencies 3. Fixed-Frequency operation, while ensuring signal filtering / interference located outside the reception band, since the antenna bandwidth =0.010. At the same time, the standard quarter-wave vertical antennas have a bandwidth of 20-200 times wider than our proposed antenna; 4. Working in the frequency scanning, which can be purposefully changed with simultaneous provision of filtering signals that lie outside of the antenna band pass. 5. The antenna, in addition to the reception or emission of signals performs the same function of a tunable narrowband band pass filter 6. When the proposed antenna combined with SDR system , the antenna can play role tunable receiver preselector, which you can control by settings of SDR system itself; 7. The antenna increases the receiver dynamic range of third-order intermodulation value IMD3 3 x A, dBa, where A - fading out of bandwidth antenna, and can be no less 20 dB on HF and VHF band. 8. Receivers SNR improving approximately 2 times 9. The compact dimensions of the antenna, especially vertical dimension 10. The antenna designs have multiple resonant frequencies, and are effective over a broad range of frequencies. The GRAT antenna has high Q-factors and resonate with greater amplitudes at the resonant frequency. But from other side high Q assumes a narrow bandwidth of resonant frequencies and lower rate of energy loss. Fast electronics tuning allows to distribute equal emitted energy with broad frequency overlap. Therefore, a high Q tuned circuit in a radio receiver has more selectivity, does a better signal-filtering from other stations that lie nearby on the spectrum. The transmitting antenna with high Q value oscillates in a narrow bandwidth, so it is more stable and emits more energy per Hertz. GRAT-Antenna: Implementation Police, ambulance, firefighters Ultra-Portable Highly-stable communication devices for emergency services. The design of antenna allows to build more efficient network. The Federal Communications Commission has mandated all public safety and business industrial land mobile radio (LMR) systems operating in the 150-512 MHz radio bands to cease operating using 25 KHz efficiency technology and begin operating on channel bandwidths of 12.5 KHz or less as of January 1, 2013. This mandate affects any users operating at VHF (150-174 MHz) (we can narrow antenna bandwidth around 150 KHz to 75 KHz on given frequency range) and UHF (421-512 MHz) (we can narrow antenna bandwidth around 250 KHz to 200 KHz on given frequency range) utilizing Part 90 frequencies. This includes but is not limited to public safety, public works, utilities, hospitals, higher education, and K-12 schools. After January 1, 2013, licensees not operating at 12.5 KHz efficiency will be in violation of the Commission's rules and could be subject to FCC enforcement action. The next generation of our antenna with contemporary equipment will improve operating benefits and decreasing device dimensions. Although a deadline for the second phase of narrowbanding, conversion to 6.25 KHz channel efficiency, has not been specified by the FCC for VHF/UHF licenses, a deadline has been established which requires 700 MHz channels to operate at 6.25 KHz efficiency by January 1, 2017. GRAT-Antenna: Implementation Emergency Situations in remote areas and areas of natural disaster. Huge improvement to the durability and mechanical stability when working in forested areas, strong winds and other natural disasters. Existing long-whip antennas are highly vulnerable to the mechanical stress. The proposed antenna due to its compact nature and mechanical strength may be a worthy substitute for them, since it is easier to protect from the unwanted environmental and other external stresses. In this case, it is maybe not as effective as classical antennas. High-speed transport, air, land, sea. Small size of the proposed antenna can provide high quality and streamlining to create it as an element of body design of a moving object. Security Systems, where the antenna can be used as part of the natural environment for stealth where necessary. Automatic unattended beacons, emergency beacons operating in harsh climatic conditions. The small size allows it to establish as an element of housing design, easy to protect from external influences while maintaining high efficiency. GRAT-Antenna: Implementation Mini, micro and nano satellites. Place of installation: metal panels of heat exchangers, solar batteries. Objective: Reduction in size of satellites with high efficiency transceivers antenna systems. On satellites, various electronic devices, with different purpose in design, frequency range and power transmitting antennas, which create strong electromagnetic fields. All this equipment is operated in a very limited extent, which leads to strong interference. Using the proposed tunable resonant antenna will eliminate the existing problem on the above described electromagnetic compatibility. Small size make it possible to place several of the proposed tunable antennas operating at different frequencies without interference. This allows for the unique physical experiments on the multi-frequency transillumination of the ionosphere over a wide frequency range. Possibility of establishing narrowband communication channel for using satellite in repeater mode. With compatible "on ground" equipment such communication session will be precise directed to the object and practically undetected by surrounding monitoring stations. The mini satellite on lower orbit relative to targeted satellite orbit can generate special interference signal to simulate malfunctioning of the communication channel or falsify GPS signal for any reason. Because of GRAT-antenna strong EMF in near zone and small, undetectable, dimension such satellite can be located near any orbital object to block receiving control signal. GRAT-Antenna: Implementation RCIED Jamming Using the proposed antenna with various existing generators interference-type jammers. The existing jamming systems now use full-length whip antenna for lower frequency band and such jammers are “power hungry” and require big amount of space. The used type of antenna is not efficient enough to generate the required field strength in the near zone at an affordable energy. The proposed antenna because of its natural properties has a much greater intensity near-field compared with counterparts with equal energy. In this case, it is, as mentioned above, is more compact, durable and better mechanically implemented. Genesys had designed RCIED Jammer based on the GRAT-Antenna. The use of GRAT-Antenna in this new jammer allows to fully explore and utilize its unique features and capabilities.