- 标题
- 摘要
- 关键词
- 实验方案
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A New Broadband Magic Tee Design for Ka-Band Satellite Communications
摘要： This letter deals with the design, electromagnetic simulation, and test results of a novel broadband Magic Tee for Ka-band (25.5–27 GHz) satellite communications. Novel matching structure is implemented in the Magic Tee, which results in better electrical performances over broad bandwidth. The designed Magic Tee is realized using electro-discharge machining fabrication technique for achieving stringent dimensional accuracy. The measured bandwidth of the Magic Tee is approximately 16% with a maximum measured in-band insertion loss of 0.2 dB. The simulation results of the developed Magic Tee are compared with measured results using a vector network analyzer showing excellent agreement. The Magic Tee introduced in this letter can be used for designing a monopulse comparator for low earth orbit satellite tracking applications since the amplitude imbalance and phase imbalance of the Magic Tee are negligible, which result in excellent tracking performances.
关键词： Magic Tee junction,monopulse comparator,monopulse tracking,satellite tracking
更新于2025-09-23 15:22:29
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[IEEE 2018 15th European Radar Conference (EuRAD) - Madrid, Spain (2018.9.26-2018.9.28)] 2018 15th European Radar Conference (EuRAD) - Target Localization Using MIMO-Monopulse: Application on 79 GHz FMCW Automotive Radar
摘要： A novel target azimuth estimation algorithm called "MIMO-Monopulse" is proposed by combining monopulse approach with multiple-input multiple-output (MIMO) radar. Chebyshev and Zolotarev weighting are applied to synthesis sum and difference pattern of MIMO-monopulse. A new visualization method for monopulse ratio is discussed. Finally, the proposed algorithm is veri?ed successfully by processing real data from a 79 GHz FMCW automotive radar.
关键词： DoA,monopulse,automotive radar,target angle estimation,FMCW,MIMO
更新于2025-09-23 15:21:21
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Multibeam Monopulse SIW Slot Array Antenna
摘要： A multibeam slot array antenna is proposed in the 10-GHz band for a monopulse tracking system with resolution enhancement techniques. The antenna architecture combines a four-subarray SIW slot antenna, a multibeam-forming network of microstrip Rotman lens array, and a SIW comparator of four-quadrant monopulse technique. A method to form difference patterns in both E-plane and H-plane for mutibeams is presented, and the method can improve the accuracy of angle detection for all beams. The key point of the method is to compensate the phase difference caused by the beam deflection between two subarrays (quadrants) by constraining input delay lines of the Rotman lens array. To validate the proposed concepts, an antenna prototype is realized and measured. The experimental results demonstrate a scanning range of ±36° with -5 dB crossover level between two adjacent sum beams in the E-plane. The corresponding beams of difference pattern are generated in E-plane and H-plane via the monopulse comparator to enhance angle resolution. The multibeam monopulse system can achieve gains between 21.7 dBi and 23.5 dBi for all sum beams at the center frequency of 10 GHz. The lobe imbalances are less than 1.1 dB and null depths are lower than -16 dB for all difference patterns. This multibeam monopulse slot antenna can be applied in radar and communication systems requiring beam-scanning capabilities and target tracking.
关键词： slot array,Rotman lens,monopulse antenna,substrate integrated waveguide (SIW),Multibeam antenna
更新于2025-09-23 15:21:01
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[IEEE SoutheastCon 2018 - St. Petersburg, FL (2018.4.19-2018.4.22)] SoutheastCon 2018 - An Examination of Dichotomous and Centroid Tracking of a Monopulse Angle Tracking Unit
摘要： The engineering community is confident in its assessment of how an angle tracker will perform in a multi-target environment as the target-to-tracker range decreases, causing targets to leave the tracker antenna beam. When one target signal dominates due to the angular separation of the targets, the tracker will center on the dominating signal. It is not well understood how the tracker will behave when angle separation is not the limiting factor in signal strength. That topic is addressed in this paper. Specifically, we show how angle error signal normalization impacts track loop dynamics in a dual target scenario. If the error signal is normalized by an Automatic Gain Control (AGC), the behavior will depend upon the Doppler frequency separation of the two targets relative to the AGC bandwidth. The problem is addressed from a theoretical perspective, and via simulation. The theoretical and simulation results agree well.
关键词： simulation,AGC,angle tracker,Automatic Gain Control,Doppler frequency,monopulse
更新于2025-09-23 15:21:01
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Compensation of Radome Effects in Small Airborne Monopulse Arrays by Convex Optimization
摘要： The quality of small array antennas in airborne monopulse systems can be significantly reduced by the radome. We therefore present a convex optimization approach to minimize radome effects in monopulse arrays. This is achieved by using active element patterns in the optimization to determine the excitation weights. Simulation results for a BoR array with 48 elements and an extended hemispherical radome are presented. We demonstrate that it is possible to reduce the side-lobe level by 3.5 dB by taking radome effects into account in the optimization. This approach also results in an increased gain, particularly at large scan angles. Furthermore, the presented approach allows the monopulse slope to be indirectly specified as a design parameter. It is shown that the trade-off between the monopulse slope coefficient and the side-lobe level is approximately linear.
关键词： radomes,airborne ESM,monopulse DOA estimation,convex optimization,phased array antennas
更新于2025-09-23 15:19:57
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3-D-Printed Modified Butler Matrix Based on Gap Waveguide at W-Band for Monopulse Radar
摘要： This article presents the design and fabrication of low-loss, -weight, and -cost, modified Butler matrix in groove gap waveguide technology at W-band, implemented by additive manufacturing. The design, simulations, and measurements of the elements that conform to the modified Butler each of matrix are presented. The proposed modified Butler matrix is asymmetric and oriented to an easy assembly with a radial antenna in order to obtain simultaneous sum and difference patterns for a narrowband radar application. The measured individual components of the modified Butler matrix fit very well with the simulations. As for the full modified Butler matrix, measurements provide a 0.7% bandwidth below ?20 dB for sum and difference ports centered at 94 GHz. The amplitude and phase imbalance are below 1.5 dB and 20?, respectively. This narrow bandwidth is due to the difference in length between input and output ports due to the asymmetry of the design. The total losses of the modified Butler matrix are below 1 dB.
关键词： low profile,distribution network,Additive manufacturing,butler matrix,low cost,W-band,point-to-point communications,low weight,groove gap waveguide (GGW),radar,low loss,monopulse,space debris
更新于2025-09-16 10:30:52
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[IEEE 2018 International Applied Computational Electromagnetics Society Symposium - China (ACES) - Beijing, China (2018.7.29-2018.8.1)] 2018 International Applied Computational Electromagnetics Society Symposium - China (ACES) - Design of Substrate Integrated Waveguide Based Filtering Antennas
摘要： In this paper, antennas with filtering responses for both input return loss and radiation gain, are analyzed by filter integrated synthesis method and designed with substrate waveguide resonators, to obtain better suppressions against out-of-band signals and functional array designs for practical applications.
关键词： dual polarization,monopulse function,substrate waveguide,signal suppression,filtering integrated antenna
更新于2025-09-11 14:15:04
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Ground moving target detection algorithm for monopulse-SAR based on complex monopulse ratio
摘要： Monopulse processing has been proved to be an effective way for airborne synthetic aperture radar (SAR)/ground moving target indication. In the monopulse-SAR system, moving target detection is applied to a complex ratio diagram, referred to as a complex monopulse ratio diagram (CMRD), generated through a pixel-by-pixel comparison between the range-Doppler (RD) spectra obtained from the difference and sum channels. This study examines the statistics of complex monopulse ratio (CMR) in the Gaussian background. Based on the statistics, a new random variable termed normalised CMR (NCMR) is derived by a linear transform to CMR. It is demonstrated that the conditional probability density function of NCMR, under the null hypothesis (H0), is independent of the clutter-plus-noise environment. Motivated by this characteristic, a constant false alarm rate detector using the modulus of NCMR as the test statistic is proposed to detect moving targets. The detection performance is evaluated with a closed-form expression of the probability of false alarm (PFA) derived. Moreover, the construction of the detector is extended to a so-called multi-CMRD form to accommodate even higher detection performance. Experimental results from two groups of real data are displayed to validate the statistical analysis and verify the detection performance.
关键词： monopulse-SAR,constant false alarm rate detector,complex monopulse ratio,Gaussian background,ground moving target detection
更新于2025-09-09 09:28:46
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Combined Constrained Adaptive Sum and Difference Beamforming in Monopulse Angle Estimation
摘要： Motivated by beams distortion in multiple interferences environment, we propose a novel combined constrained method for adaptive sum and difference beamforming in monopulse angle estimation. By optimizing the adaptive weights of sum and difference beams jointly, the restriction on the degree of freedom to determine the adaptive sum or difference weight is evenly distributed to all weights. The constraints of array gain and monopulse ratio curve are utilized to avoid beams distortion while nulling the interferences. Simulations of the proposed algorithm have been provided which show a signi?cant improvement in beamforming and angle estimation performance compared to the conventional constrained adaptive monopulse algorithm.
关键词： degree of freedom,monopulse angle estimation,interference cancellation,combined constrained,Adaptive beamforming
更新于2025-09-09 09:28:46
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[IEEE 2018 15th European Radar Conference (EuRAD) - Madrid, Spain (2018.9.26-2018.9.28)] 2018 15th European Radar Conference (EuRAD) - A Compact Simultaneous K/S-Band Monopulse Tracking Feed for Future Earth Observation Applications
摘要： This paper presents a novel K/S band monopulse tracking feed for the next generation of Earth Observation (EO) applications in the 25.5 to 27 GHz band. A brief review of the feed, which covers the design and development of a dual band coaxial horn, a TE21 resonant tracking coupler, OMTs and polarizers (septum and corrugated), is included. Characterization of the complete feed in both bands is also summarized in the paper, as well as the evaluation of several dielectric materials for the radome feed window, which is particularly critical in K-band.
关键词： earth observation,coaxial waveguide feed,TE21 monopulse tracking
更新于2025-09-04 15:30:14