A High Performance Integrated Circuit for Successive Detection Logarithmic Amplifiers

An improved method of reducing the input impedance of a four-arm sinuous antenna is demonstrated for a wide gain bandwidth. The proposed antenna has a dual-linear polarized response for electronic support measures (ESM) systems and is designed with a planar substrate. The structure for reducing the input impedance is developed based on the transmission and coupled line theory and is shown to be in excellent agreement with theoretical predictions. The proposed antenna achieves an impedance bandwidth in the range of 0.45–6 GHz with a reference impedance of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$100 ~\Omega $ </tex-math></inline-formula> . Simulations for comparison according to the difference in input impedance of designed antennas with feeding structures are also presented. Finally, the performance of the fabricated antenna with wideband balun is verified by measuring co- and cross-polarization radiation patterns. As a result, the proposed antenna achieves a wide gain bandwidth (>2.5 dBi) and a cross-polarization isolation (>−13 dB) of more than 12:1 in the frequency range over 0.6 GHz, which can be used in ESM systems.

This paper covers development trends in communication and radar electronic warfare (EW). Threat scenario and role of EW sensors in developing Electronic Order of Battle (EOB) are described. EW is subdivided into Electronic Support Measure (ESM), Electronic Counter Measure (ECM) and Electronic Counter-counter Measure (ECCM) systems. Developments in communication ESM and ECM systems and their constituents are described. Under COM ECM, jammer system configuration and realisation of the constituent subsystems, jamming strategies used for effectively countering various types of communications are described. Developments in critical subsystems and configurations of typical radar EW systems are discussed. Finally the status of the indigenous developments in ESM, ECM and integrated systems are described.

Since cognition has become an important topic in Electronic Warfare (EW) systems, Electronic Support Measures (ESM) are used to monitor, intercept and analyse radar signals. Low Probability of Intercept (LPI) radars is preferred to be able to detect targets without being detected by ES systems. Because of their properties as low power, variable frequency, wide bandwidth, LPI Radar waveforms are difficult to intercept with ESM systems. In addition to intercepting, the determination of the waveform types used by the LPI Radars is also very important for applying counter-measures against these radars. In this study, a solution for the LPI Radar waveform recognition is proposed. The solution is based on the training of Support Vector Machine (SVM) after applying Principal Component Analysis (PCA) to the data obtained by Time-Frequency Images (TFI). TFIs are generated using Choi-Williams Distribution. High energy regions on these images are cropped automatically and then resized to obtain uniform data set. To obtain the best result in SVM, the SVM Hyper-Parameters are also optimized. Results are obtained by using one-against-all and one-against-one methods. Better classification performance than those given in the literature have been obtained especially for lower Signal to Noise Ratio (SNR) values. The cross-validated results obtained are compared with the best results in the literature.

Electronic support measures (ESM) systems use different methods for direction finding (DF). Performance of a DF antenna array is an essential measure of the overall ESM system. A common DF method of phase interferometry using a circular interferometer is discussed. Typically a circular interferometer employs a polarizer to match the desired incident polarizations to the polarization of the antenna array. This paper describes a simulation method for evaluation of polarizer impact on direction finding performance of a circular interferometer. Simulation of DF antenna performance of a circular interferometer with and without a polarizer, using method-of-moments antenna simulation and spreadsheet based post-processing. The benefits of simulation include being a cost effective way of performance prediction for a new design or for the influence of installation structures on an existing system. Sample DF accuracy results are discussed and compared to previously published specifications. This work is based on analysis conducted on the ESM system for the surface combatant force guided missile frigates (FFG ) upgrade project.

This paper investigates integrated waveform design for radar systems to simultaneously achieve a low probability of intercept (LPI) by an adversary electronic support measure (ESM) system while maintaining communications with other radar nodes. A reconfigurable intelligent surface (RIS) is exploited and jointly designed to enhance the achievable performance of the whole system. LPI detection based on the ESM’s feature analysis on the radar waveform is achieved under the constraints of a desired signal-to-interference-and-noise ratio for the radar detection and a desired signal-to-noise ratio-based quality of service for the communication channels. To deal with the resulting non-convex optimization problem, a suboptimal composite algorithm with polynomial complexity is proposed. The initial feasible solution of the algorithm is efficiently obtained through an asymptotic optimization problem. Finally, the complexity of the proposed algorithm is analyzed. Simulation results including comparisons with baselines highlight the effectiveness of the proposed scheme.

Detection of the changes in Multi-Functional Radar (MFR) work modes is a critical situation assessment task for Electronic Support Measure (ESM) systems. There are two major challenges that must be addressed: (i) The received radar pulse stream may contain multiple work mode segments of unknown number and duration, which makes the Change Point Detection (CPD) difficult. (ii) Modern MFRs can produce a variety of parameter-level (fine-grained) work modes with complex and flexible patterns, which are challenging to detect through traditional statistical methods and basic learning models. To address the challenges, a deep learning framework is proposed for fine-grained work mode CPD in this paper. First, the fine-grained MFR work mode model is established. Then, a multi-head attention-based bi-directional long short-term memory network is introduced to abstract high-order relationships between successive pulses. Finally, temporal features are adopted to predict the probability of each pulse being a change point. The framework further improves the label configuration and the loss function of training to mitigate the label sparsity problem effectively. The simulation results showed that compared with existing methods, the proposed framework effectively improves the CPD performance at parameter-level. Moreover, the F1-score was increased by 4.15% under hybrid non-ideal conditions.

The field of circular (or cylindrical) arrays has received far less attention than that devoted to linear and planar arrays. At first sight this seems surprising since one of their principal advantages is the ability to deflect beams electronically through 360° with little change of either beamwidth or sidelobe level. Circular arrays have been applied, to a limited extent, in both communication systems and navigational aids since the late 1930s. There has, however, been surprisingly little change in their scale of application since that date, though there are now signs of a significant increase of interest in such arrays for applications to DF (Direction Finding) and ESM (Electronic Support Measures) systems. The analysis and general understanding of the properties of circular arrays has progressed steadily for many years and the most significant developments were probably made by several groups of workers in the 1960s when the concept of phase mode excitation was developed. The lack of applications in the past is prob ably due to the fact that the basic problems of exciting circular arrays with the correct values of amplitude and phase are, in general, more complex than for linear arrays. Furthermore, electronic scanning of directional patterns for circular arrays may be difficult to implement and can require both the amplitude and phase of each element of the array to be changed.

In this paper, a low cost and high performance current and voltage measurement system designed for application in medium voltage inverters is proposed. The main features of the proposed system are the use of commercially available integrated circuits and signal transmission from sensing point to the control board through an optic fiber link. Three single-bit oversampling analog to digital conversion systems are considered in this study. Simulation and experimental results are presented to confirm the high performance of the proposed measurement system.

This paper presents data on the single event transient (SET) response of several high speed commercial fiber optic links (FOLs). We show that commercial-grade technologies may be robust to SET in the natural space environment encountered in many satellite missions even for data rates in the 1Gbps regime. In addition to characterizing the error cross section as a function of optical power and data rate, the angular dependence of the SET behavior is also quantified as a function of optical power. Note that receiver angular response has some similarity to behavior observed in optocoupler technology and must be quantified for accurate predictions of on-orbit link error rates.

ABSTRACTThis article measured the stability of the transmission of the coaxial cable and introduced a measurement system using the optical fiber link technologies in the millimeter‐wave band. The radiation patterns of two antennas have been measured by the proposed optical fiber link system at 60 GHz. The proposed system is a reliable candidate for the small antenna pattern measurement system in the millimeter wave band. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:201–204, 2017

Precise time and frequency signal transfer over a long distance is one of the key activity in time and frequency metrology as precise time plays critical roles in many of the advanced technology as well as in scientific research. Since, last few decades optical fibre-based time and frequency signal transfer techniques has attracted immense importance as optical fibre-based methods show very low instability over long distances in various configurations. This article presents the time synchronization of a remotely located clock with a reference atomic clock over a 10 km long optical fibre link within an uncertainty of 100 ps. Effect of ambient conditions mainly temperature variations on the White Rabbit (WR) based optical fibre link has been studied and a simple method to mitigate the effect of ambient variation on time synchronization accuracy has been presented. Stability of the phase compensated optical fibre link in terms of modified Allan deviation is reaching ~ 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">–16</sup> within one day of integration time and time deviation goes down to 2.2ps at 256 sec integration time.

In this paper, a simple and small dimension circular corrugated horn antenna at C-band frequency with high gain performance is designed. This antenna is designed for ESM (Electronic Support Measure) application with antenna dimensions is 43 x 155 mm using copper as the antenna material. The circular corrugated horn antenna is designed and simulated using CST Microwave Studio Suite software. The simulation shows results with gain 15.91 dBi, bandwidth 4.3 GHz and linear vertical polarization. This antenna has beamwidth of 45.7° at H-field and 38.9° at E-field.

We have proposed the optical fiber link antenna measurement system that can measure the calibrated S11 and S21 between two antennas under test (AUT) after OSLT calibration in one-pass two-port system. Our system consists of the transmitting and receiving optical-fiber link systems. The transmitting system consists of the electro-absorptive modulator, erbium doped fiber optical amplifier (EDFA), optical fiber, zero biased uni-traveling-carrier photodiode (UTC-PD), small type bi-directional coupler, and two optical reflection type Mach-Zehnder LiNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> optical intensity modulators (LN-modulators) with 50 ohm loads. The system can detect the reflection signal from the transmitting AUT and the reference signal toward the AUT. The receiving system consists of an optical reflection type LN-modulator and the optical field measurement system, to measure the transmission signal through the receiving AUT. Our system can measure the reference signal, the reflection signal, and the transmission signal in one-pass two-port model between the two AUTs. Then OSLT calibration can be adopted. In this paper, in order to demonstrate the validity of our optical fiber link system, we compare the calibrated S11 and S21 results of two UHALP9108A 1 Log-periodic antennas by our proposed optical-fiber link system with the ones by the conventional coaxial cable system in frequency-domain and time-domain measurements. The results clearly indicate that our proposed system can be used to evaluate the S11 and S21 of the AUT at the frequency range from 300 MHz to 1800 MHz without coaxial cables.

De-multiplexing the required spectrum in a traffic demand into multiple non-adjacent granular spectrums for dynamic traffic grooming in EON

DOI: 10.1049/ic:20070402 ISBN: 978-3-8007-3042-1 Location: Berlin, Germany Conference date: 16-20 Sept. 2007 Format: PDF We demonstrate theoretically and experimentally that the differential group delay and differential attenuation slope of an optical fiber with polarization-dependent loss can be explicitly obtained by reflectometric measurements in optical frequency and fiber length domains. (2 pages) Inspec keywords: polarisation; optical links; optical dispersion; reflectometry Subjects: Optical variables measurement; Optical fibre networks