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Communications, Radar and Signal Processing, IEE Proceedings F

Issue 3 • Date June 1982

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Displaying Results 1 - 15 of 15
  • Introduction to electronic warfare

    Page(s): 113 - 132
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (3554 KB)  

    The paper discusses the overall concept of electronic warfare (EW) and defines its three main subsets: electronic support measures (ESM), electronic countermeasures (ECM) and electronic counter-countermeasures (ECCM). The requirements for ESM receivers are reviewed in the context of two specific scenarios: that of intelligence gathering for communications and radar. The different current ESM receiver designs for measuring the presence and frequency of pulsed radar signals, i.e. crystal video, instantaneous-frequency measurement (IFM) and scanning superheterodyne, are described and compared to show their capabilities. Specific ESM receiver equipments for identifying bearing and frequency information are discussed for both the communications and radar scenarios. In comparison, the significance of the new receiver architectures based on surface-acoustic-wave (SAW) channelised, compressive and acousto-optic Bragg cells are also discussed, illustrating their enhanced multiple-signal capability. The paper subsequently discusses active and passive EW techniques such as the use of jamming and chaff and the importance of integrating the ESM receiver and active ECM function into a single equipment. Finally, the paper reports on the use of ECCM coding techniques to retain use of the spectrum when jammers are present in radar and communications systems. The use of adaptive signal processing for cancelling out wide- and narrowband interference is also demonstrated. This outlines the relative significance and areas of application for adaptive antennas, based on fully phased arrays and coherent sidelobe cancellers. View full abstract»

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  • Broadband crystal video front end for radar warning receivers

    Page(s): 133 - 137
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (661 KB)  

    The paper describes a broadband crystal video receiver, optimised for use in radar warning receivers with a direction-finding capability. The system design and the technologies adopted have been chosen to obtain a small, light and reliable line-replaceable unit that requires no particular adjustment to interface with other circuits. The receiver features a frequency-band-sorting capability to improve performance in a dense electromagnetic environment and is equipped with the important complementary functions of an internal voltage regulator and an RF test source. View full abstract»

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  • Multiplexers and their integration with crystal video receivers

    Page(s): 138 - 142
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (754 KB)  

    Broadband, highly selective, low-loss contiguous multiplexers have been developed in the form of suspended-substrate-stripline (SSS) devices. These multiplexers can have channel bandwidths covering at least an octave (up to a decade for the lowest-frequency channel) with a passband insertion loss less than 1 dB and stopband attenuations greater than 60 dB within only 5% of the crossover frequencies. Moreover, these devices can be made extremely thin and lightweight; typically, a diplexer covering an octave band per channel weighs less than 15g. The suspended-substrate-stripline approach enables the direct integration of other microwave components onto the substrate to produce complete high-performance subsystems. A DC-coupled crystal log video receiver weighing only 230 g and enclosed in a 7.5 in3 box has been produced to cover the bands 4¿¿8, 8¿¿12 and 12¿¿18 GHz using the above ideas. View full abstract»

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  • Direct video detection with wideband amplification

    Page(s): 143 - 153
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (996 KB)  

    A theoretical approach has been developed that allows an insight into the operational performance of crystal video ESM systems and agrees with some experimental observations. Probability-density functions for the outputs of wide-bandwidth-ratio microwave receivers that incorporate square-law detectors have been determined. The utilisation of the above functions in the solution of problems, both in operational assessment and in a cost-effective electronic-warfare systems design, is shown. View full abstract»

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  • Design techniques and performance of digital IFM

    Page(s): 154 - 163
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1542 KB)  

    The digital instantaneous-frequency-measuring receiver using delay-line discriminators was developed in the early 1960s specifically as a wideband and accurate analyser of pulsed radar signals. Various receiver configurations are incorporated in most of the more comprehensive EW systems currently in use. In the paper, the basic operating principles and design philosophy are reviewed, together with an indication of the performance presently achieveable in the field using modern MIC technology and digital signal-processing techniques. Component and operational factors affecting accuracy, sensitivity, dynamic range and band coverage are discussed. The instantaneous-frequency-following capability is assessed, including means of extracting or displaying information from frequency- or phase-modulation-on-pulse-type signals. Problems arising when multiple signals, pulse or CW, are present simultaneously can be overcome to a certain extent by using the large-signal capture effect in limiting RF preamplifiers. The degree of measurement integrity under these conditions is related to receiver design factors, and processing methods are described which can be used to identify ambiguous measurements when these occur. Finally, some practical implementations are given of digital instantaneous-frequency measurement in ESM and ECM equipments. View full abstract»

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  • Automatic processing for ESM

    Page(s): 164 - 171
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1677 KB)  

    In the past, radar ESM systems have relied on operator interpretation of measured parameters to provide classification and identification of emitters. However, for rapid response in the dense electromagnetic environments encountered in modern warfare, automatic processing and decision-making techniques are required. In order to identify individual emitters, their pulse trains must be deinterleaved. Various approaches to deinterleaving are discussed, and the relative merits of emitter parameters for each method are identified. Since it is impossible to totally avoid data corruption before the sorting process, the system design must take this into account. View full abstract»

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  • Channelised receiver. A viable solution for EW and ESM systems

    Page(s): 172 - 179
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1251 KB)  

    The requirements of EW and ESM receivers continue to become more and more demanding. The channelised receiver is one receiver type that can often meet, or exceed, these demanding requirements. The paper presents discussion suggesting that he recent success of the channelised receiver is largely due to technology advances in areas such as surface-acoustic-wave filters, microprocessors and microwave integrated circuits. The paper presents a brief description of two recently developed systems, both of which make extensive practical use of surface-wave components. A brief discussion on the recurring concern of how to optimally multiplex filters is also presented. View full abstract»

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  • SAW compressive receivers for radar intercept

    Page(s): 180 - 186
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1047 KB)  

    The choice of transform parameters for SAW radar intercept is dictated by the limitations of available digital output stages and by the nature of the input signal, rather than by limitations imposed by the surface-acoustic-wave components. The choice of parameters needed to design a radar-intercept compressive receiver for use in a pulsed-signal environment is discussed, as is the resulting `trade-off¿¿ between time and frequency resolutions. Details are given of a compressive receiver where a modular approach has been adopted to produce a SAW subsystem with 4 MHz resolution over 1 GHz input bandwidth. The problem of high output data rates has been overcome by the use of specially designed digital output circuits to interface to a data processor. View full abstract»

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  • Integrated optic spectrum analyser

    Page(s): 187 - 193
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1202 KB)  

    The integrated optic spectrum analyser (IOSA) utilises the Bragg refraction of an optical guided beam by a surface-acoustic wave to perform spectral analysis. The recent development of this device has been carried out by several groups in the USA. These researchers, while working towards similar performance goals, have each achieved varying degrees of success using differing technological implementations. The paper reviews the results of these efforts and provides an overview as to the current status of IOSA development. The paper begins with the design of the IOSA optics. Next, the techniques used for lens fabrication are discussed. This is followed by a description of the types of SAW transducers used. The detector arrays studied to date are briefly described. Finally, the performance characteristics of the IOSAs that have been developed are discussed. View full abstract»

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  • Integrated naval EW systems

    Page(s): 194 - 196
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (405 KB)  

    A review of the role of electronic-warfare sensors in a modern naval environment is made. Certain operational requirements for the detection, identification and response to a threat are identified. From this, a functional solution for an integrated electronic-warfare system is presented. View full abstract»

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  • Chaff

    Page(s): 197 - 201
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (714 KB)  

    The paper reviews the development of chaff as an electronic-countermeasures (ECM) technique and describes the basic principles of chaff as reflectors of radar waves. The various common types of chaff are described, including their main physical and aerodynamic characteristics. Some illustration of the use of chaff is given in naval and airforce applications. View full abstract»

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  • Effectiveness of a ground jammer

    Page(s): 202 - 207
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (810 KB)  

    The effectiveness of a noise jammer can be expressed in terms of the radar range where aircraft detection occurs. A simple equation is developed for computing the screening range of a search radar against which a noise jammer operates. Fundamental information about the victim radar is needed. All the radar parameters required for the computation of the screening range can be measured in the field. The equation has been verified in practice and its accuracy found satisfactory. View full abstract»

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  • Microwave frequency dividers: devices and applications

    Page(s): 208 - 212
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (720 KB)  

    Microwave frequency dividers are fundamental new devices which employ subharmonic generation to provide accurate frequency division by two over microwave octave bands. Unlike mixer-type down con-vertors, these devices require no local oscillator. Furthermore, each successive stage halves the bandwidth, permitting a wideband input to be mapped into a narrowband output where analogue or digital processing can easily be accomplished. These properties are directly applicable to improving the performance of electronic countermeasures equipment, communications systems and laboratory instruments. At the Defence Research Establishment Ottawa, an experimental ultrabroadband countermeasures system is being developed which uses frequency division, digital signal manipulation and frequency multiplication. The system compresses the frequency range from 125 MHz¿¿15 GHz, in octave bands, into the 125¿¿250 MHz band for digitisation. Once digitised, the signal may be analysed, classified or manipulated to produce coherent jamming signals to counter frequency-agile, Doppler or coded waveforms. View full abstract»

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  • Jaguar-V frequency-hopping radio system

    Page(s): 213 - 222
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1363 KB)  

    The electronic threat to VHF tactical communications systems is reviewed, and possible counter-measures are discussed. The principles of the Jaguar-V frequency-hopping system are described, together with some aspects of the radio-system design and technical features of its implementation. Operational aspects of system performance are also discussed. View full abstract»

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  • Adaptive arrays for communications

    Page(s): 223 - 232
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1593 KB)  

    The basic principles of adaptive arrays are outlined, emphasising the requirements of such arrays for communications, as distinct from radar. These arrays are designed so that they automatically adapt their responses to give low gain to unwanted signals, while maintaining adequate gain to a wanted signal. The basic approaches to achieving this aim are described, with some comment on the relative merits of different systems in terms of cost, complexity and performance. Some practical aspects affecting design and performance are discussed and references are made to actual systems. View full abstract»

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Aims & Scope

The latest version of this title is Radar, Sonar & Navigation, IET.

Full Aims & Scope