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Waveforms Search for Noncoherent pulse compression

IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE 2024年第4期39卷 32-40页

作者： Levanon, Nadav Cohen, Itzik Tel Aviv Univ Fac Engn IL-6997801 Tel Aviv Israel Weizmann Inst Sci Fac Math & Comp Sci IL-7610001 Rehovot Israel

Radar pulse compression is a prevalent radar technique that increases the bandwidth of a coherent radar pulse by intrapulse frequency modulation or phase coding. A matched filter (MF), used on receive, causes a long weak pulse to exhibit delay properties of a narrow strong pulse. Longer mismatched filters (MMF) are often used to lower the sidelobes of the delay response, with a penalty of a small loss in the signal-to-noise ratio. This article reviews techniques that extend this important concept to noncoherent sensors whose only emitted coding option is on-off (e.g., direct detection LIDAR). It shows that processing by a mismatched filter is obligatory rather than optional. It discusses merit measures and presents search results of medium-length, good, on-off sequences. The article covers also periodic on-off sequences, corresponding to continuous wave radar. Here the on receive MMF is replaced by a same period-length, real-valued, reference sequence, exhibiting perfect (sidelobe-free) periodic cross-correlation, with the emitted on-off periodic sequence. Detection in the presence of noise is demonstrated through Monte-Carlo simulations.

关键词： Codes Laser radar Signal to noise ratio Radar Matched filters Delays Encoding Sensors Monte Carlo methods Frequency modulation Channel allocation Noise measurement pulse compression methods Signal processing Coherent detection

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A Simple Yet Effective Metric for Assessing Doppler Tolerance

IEEE TRANSACTIONS ON RADAR SYSTEMS

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IEEE TRANSACTIONS ON RADAR SYSTEMS 2023年 1卷 12-20页

作者： Quirk, Jennifer E. Chang, Rachel J. Owen, Jonathan W. Blunt, Shannon D. McCormick, Patrick M. Univ Kansas Radar Syst & Remote Sensing Lab RSL Lawrence KS 66045 USA Univ Kansas Dept Elect Engn & Comp Sci EECS Lawrence KS 66045 USA

The Doppler tolerance of a waveform refers to its behavior when subjected to fast-time Doppler shift imposed by scattering that involves nonnegligible radial velocity. The delay/Doppler ambiguity function characterizes this behavior, with notable attributes of Doppler-dependent mismatch loss (relative to zero Doppler) and possible offset in delay estimation. Previous effort has gone into establishing decision-based criteria where a binary judgement of being Doppler tolerant or not is made. Here, we consider the utility of a simple, yet effective measure of the degree of Doppler tolerance arising from a fundamental attribute of the ambiguity function that is also convenient to extract. This metric is examined in the context of a variety of different waveform classes including traditional linear/nonlinear chirps, noise-like signals, and phase codes. Extension to wideband operation is likewise considered. The purpose in doing so is to establish a consistent standard that can be readily applied, thereby permitting easy assessment across different parameterizations, as well as introducing a Doppler "quasi-tolerant" trade-space that can ultimately inform automated/cognitive waveform design in increasingly complex and dynamic radio frequency (RF) environments.

关键词： Doppler effect Radar Doppler radar Measurement Chirp Wideband OFDM Radar signal processing pulse compression methods signal analysis

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A New Approach to Formation and Directed Radiation of Powerful Short Radio pulses

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IEEE TRANSACTIONS ON PLASMA SCIENCE 2022年第10期50卷 3422-3433页

作者： Sirenko, Yuriy Sautbekov, Seil Yashina, Nataliya Sirenko, Kostyantyn Natl Acad Sci Ukraine O Ya Usikov Inst Radiophys & Elect Dept Diffract Theory & Diffract Elect UA-61085 Kharkiv Ukraine VM Karazin Kharkiv Natl Univ Dept Appl Math UA-61022 Kharkiv Ukraine Al Farabi Kazakh Natl Univ Dept Phys & Technol Alma Ata 050040 Kazakhstan

This article details a new method for formation and directional radiation of short high-power electromagnetic (EM) pulses, which is based on a wave analog of the Smith-Purcell effect. The presented device cycles through two stages. At the stage of energy accumulation, a slow wave of an open guiding structure interacts with a periodic chain of storage resonators and excites high-Q free field oscillations in each resonator of this chain. The phase of oscillations inside the storage resonators differs by a constant value, and the amplitude increases with time. At the radiation stage, the chain of storage resonators is opened to radiation (as it usually happens in active compressors of EM pulses), and short powerful pulses burst out into free space in strictly defined directions. The proposed design is considered in detail for the simplest model of a device. The results obtained during its rigorous electrodynamic analysis look rather promising;the continuation of this work can contribute to solving a number of urgent problems of physics and technology of millimeter and submillimeter waves.

关键词： Resonators Compressors Dielectrics Diffraction Planar waveguides Surface waves Mathematical models Accumulation of electromagnetic energy active compression of electromagnetic pulses antenna arrays boundary conditions boundary value problems computational electromagnetics electromagnetic analysis electromagnetic radiation exact absorbing conditions lamellar gratings leaky wave antennas planar dielectric waveguides powerful short pulses pulse compression methods time-domain analysis

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Comparative Studies of High-Voltage Diode-Dynistor Generators of High-Power Nanosecond pulses

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IEEE TRANSACTIONS ON PLASMA SCIENCE 2022年第4期50卷 954-958页

作者： Korotkov, Sergey Aristov, Yury Zhmodikov, Alexander Ioffe Inst Solid State Elect Dept St Petersburg 194021 Russia

The results of comparative studies of two compact generators of nanosecond high-voltage pulses are presented. Both generators include an opening switch in the form of a block of drift step-recovery diodes (DSRDs) and a closing switch in the form of a block of shock-ionized dynistors (SIDs). The generators are designed according to two different schemes, but they have similar parameters of the output pulses on a load of 50 Omega: the amplitude of the output voltage is similar to 30 kV, its rise time is similar to 3 ns, and the output energy is similar to 0.4 J. It is shown that it is possible to increase the output voltage and output energy of the generators.

关键词： High-voltage techniques power semiconductor switches pulse compression methods pulse generation silicon devices

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Radar-Based Velocity Estimation Using Three-Dimensional Cross-Correlation

Radar-Based Velocity Estimation Using Three-Dimensional Cros...

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IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNeT)

作者： Scherhaeufl, Martin Pichler, Kurt Keintzel, Georg Linz Ctr Mechatron GrnbH Area Sensors & Commun Linz Austria Primet Technol Austria GmbH Technol & Innovat Rolling Mills Linz Austria

ISBN: (纸本)9781665434652

This work presents a radar-based method to determine the velocity of objects that move perpendicular to the radar beams of two 77GHz radar units. The radar modules are equipped with patch antenna arrays which can be poorly aligned with a known spacing in the direction of movement. Using pulse compression techniques and digital beamforming, the two-dimensional spectra of the acquired radar signals are calculated. By performing a three-dimensional cross-correlation to a series of these spectra, the delay in time as well as possible offsets due to the poor antenna alignment are estimated, allowing the average speed of the target to be determined. Experiments conducted under industrial conditions show that the proposed method is well suited to accurately determine the velocity of objects moving perpendicular to the radar beams.

关键词： Correlation frequency modulation pulse compression methods radar measurements radar signal processing velocity measurement

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Observations and Design Considerations for Spaceborne pulse compression Weather Radar

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IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2021年第6期59卷 4535-4546页

作者： Beauchamp, Robert M. Tanelli, Simone Sy, Ousmane O. CALTECH Jet Prop Lab 4800 Oak Grove Dr Pasadena CA 91109 USA

pulse compression has enabled a new generation of low-cost and compact spaceborne weather radar systems. To successfully utilize pulse compression techniques for cloud and precipitation applications, the effects of Doppler-range migration must be considered during the design and operation of the radar. pulse compression for spaceborne weather applications introduces additional interdependence between the radar system and the operations when compared with traditional pulsed radar systems, primarily as a result of the large platform velocities. pulse compression signals for weather radar can be simulated with high fidelity to predict and optimize the radars performance. In this article, we evaluate the pulse compression performance of RainCube, a Ka-band precipitation radar in a CubeSat, through analysis and comparison of observations and radar simulations. Through these comparisons, design and operational considerations for pulse compression weather radar are discussed. This work shows that the optimal pointing angle for RainCube to achieve the finest vertical resolution is not at nadir, but when pointing forward approximately 2.25 degrees in the direction of the spacecrafts orbit.

关键词： Spaceborne radar Doppler radar Doppler effect Meteorological radar Meteorology Radar applications Doppler effect meteorological radar pulse compression methods spaceborne radar

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Photonics Generation of Baseband-Free Arbitrary-Phase-Coded Microwave Waveform pulse

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IEEE PHOTONICS TECHNOLOGY LETTERS 2021年第9期33卷 457-460页

作者： Song, Chunqi Huang, Shanguo Gao, Xinlu Zheng, Zhennan Song, Xiyao Bai, Yunping Gao, Guanjun Ma, Jingcan Beijing Univ Posts & Telecommun State Key Lab Informat Photon & Opt Commun Beijing 100876 Peoples R China

A photonics system for baseband-free arbitrary-phase-coded microwave waveform pulse (APCMWP) generation is proposed and demonstrated. The proposed system realizes the generation of APCMWP, and further solves the baseband components problem in the pulsed process. The system uses a polarization-multiplexing dual-drive Mach-Zehnder modulator (PM-DMZM) and an optical band pass filter (OBPF) to obtain a polarization-multiplexed single-sideband modulated (SSBM) optical signal with carrier intensity-phase modulation, then uses a balanced photodetector (BPD) to properly detect the polarization-multiplexed SSBM optical signal, APCMWP with baseband components suppression can be easily generated. A detailed theoretical analysis and a proof-of-concept experiment are provided. The generations of 1.2-GBaud 9.6-GHz and 2-GBaud 12-GHz baseband-free APCMWP are verified.

关键词： Radio frequency Optical polarization Optical modulation Optical filters Optical mixing Optical pulse compression Baseband Microwave photonics phase code pulse compression methods

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9.1-fs pulse Generation From 10 nJ Yb-Fiber Laser with Cascaded Nonlinear pulse compression

9.1-fs Pulse Generation From 10 nJ Yb-Fiber Laser with Casca...

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Conference on Lasers and Electro-Optics (CLEO)

作者： Donguhn Kang Toshio Otsu Shuntaro Tani Yohei Kobayashi The Institute for Solid State Physics The University of Tokyo Chiba Japan

we achieved a pulse duration of 9.1 fs at 10 nJ pulse energy by adopting a two-stage nonlinear pulse compression scheme with single-mode fibers (SMF) at a 90 MHz repetition rate.

ISBN: (纸本)9798350369311

we achieved a pulse duration of 9.1 fs at 10 nJ pulse energy by adopting a two-stage nonlinear pulse compression scheme with single-mode fibers (SMF) at a 90 MHz repetition rate.

关键词： pulse generation pulse compression methods pulse measurements Surface emitting lasers Lasers and electrooptics Laser modes Mirrors Quantum cascade lasers Optical fiber dispersion Fiber lasers

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Segmented pulse compression Method for Separating Interrupted Sampling Repeater Jamming Using Morphological Closing

Segmented Pulse Compression Method for Separating Interrupte...

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IEEE International Conference on Signal and Image Processing (ICSIP)

作者： Jinkun Chen Shanhong Guo Yumin Chen Jing Yan School of Electronic and Optical Engineering Nanjing University of Science and Technology Nanjing China

ISBN: (数字)9798350350920

ISBN: (纸本)9798350350937

Interrupted sampling repeater jamming (ISRJ) based on digital radio frequency memory (DRFM) can achieve partial pulse compression gain by combining with radar signals, and has both suppression and deception interference effects. On the basis of in-depth research on intermittent sampling repeater jamming, a pulse compression method based on morphological closing separation is proposed based on its time-domain discontinuous sampling characteristics. This algorithm uses segmented pulse compression to decompose the broadband pulse compression gain of intermittent sampling and forwarding interference, and then utilizes the step characteristics of discontinuous sampling signals after segmented pulse compression to separate the segmented pulse compression signal of interference and target through closed operation, and finally accumulate it within the pulse. Theoretical analysis and simulation verification show that this method can effectively suppress various types of interrupted sampling repeater jamming without any prior knowledge.

关键词： pulse compression methods Image coding Morphology Interference Radar Object detection Repeaters

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Generation of Waveform-Controlled Optical pulses of Arbitrary Width in a Linear, Causal Dielectric: An Approach Based on Asymptotic Analysis 15

Generation of Waveform-Controlled Optical Pulses of Arbitrar...

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15th European Conference on Antennas and Propagation (EuCAP)

作者： Balictsis, Constantinos M. Zygiridis, Theodoros T. Hellen Telecommun & Post Commiss EETT Athens Greece Univ Western Macedonia Dept Elect & Comp Engn Kozani 50131 Greece

ISBN: (纸本)9788831299022

The unified asymptotic approach is employed herein and yields an analytic description of the input pulse wave, which is required in order to generate a desired waveform-controlled Gaussian pulse envelope chirped harmonic optical wave of arbitrary width at a fixed, arbitrary propagation distance in a linear, dispersive and absorptive dielectric. The dependence of this analytic approach on the input field, medium parameters, and propagation distance is elaborated and its accuracy is verified upon comparison with depicted results of numerical experiments.

关键词： computational electromagnetics electromagnetic propagation optical pulses pulse compression methods pulse shaping methods ultrafast optics

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