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Yan X.,Wuxi Institute of Technology | Yan X.,Aviation Key Laboratory of Science and Technology on AISSS | Yuan Y.,Wuxi Institute of Technology | Yuan Y.,Aviation Key Laboratory of Science and Technology on AISSS
Lecture Notes in Electrical Engineering | Year: 2016

A design of fed-divider is provided for ridge waveguide antenna array. The equivalent model of fed-slot is deduced and the fed-slots are calculated accurately at first. Based on the analytical model, the design equations are investigated by considering parameters of single-ridged fed-waveguide, double-ridged radiation waveguide and the electrical performances of array. Then, three typical slotted waveguide arrays are setup and simulated. The calculated results illustrate that the slotted ridgewaveguide antenna array,which is designed by themethod proposed in this paper, has thewidest bandwidth,where the work band is from9. 4 to 10. 1GHz, inwhich the VSWR and the magnitude-phase insistence of each element are excellent. The validity of this design method is confirmed and the fed-divider design is suitable for slotted ridge waveguide antenna in any frequency and dimension. © Springer India 2016.


Guo X.,Wuxi Institute of Technology | Guo X.,Aviation Key Laboratory of Science and Technology on AISSS | Shen J.,Wuxi Institute of Technology | Shen J.,Aviation Key Laboratory of Science and Technology on AISSS | And 2 more authors.
Lecture Notes in Electrical Engineering | Year: 2016

Novel slots have been designed synthetically for suppressing the harmonic of Vivaldi antenna in this paper. Two sorts of slots are proposed comprehensively to restrict the occurrence of second harmonic of antenna first. Second, transmission characteristics are given out between two types of feed lines. Finally, the return loss and realized gain of active integrated antenna between 8 and 24 GHz are simulated to show the validity of design. Contrast to the conventional Vivaldi antenna strategy, novel slot structure for harmonic suppression is effective without impacting on the return loss and the radiation characteristics within operational band. © Springer India 2016.


Ting Z.,AYIC Radar and Avionics Institute | Ting Z.,Aviation Key Laboratory of Science and Technology on AISSS | Bingyun S.,AYIC Radar and Avionics Institute | Bingyun S.,Aviation Key Laboratory of Science and Technology on AISSS
IET Conference Publications | Year: 2013

A novel linear antenna array, combined dual-polarization with parallel-series-fed.is introduced in this paper. The type of the antenna is slot-coupled microstrip patch. Antenna consists of twenty microstrip patches. Antenna is designed in the frequency ranges about Ku-bancls. The antenna array is series-fed so it is very easy to fabricate and quite low lost. The theoretical of return loss, isolation, and radiation patterns are presented and discussed.


Huang T.,Beijing Institute of Technology | Huang T.,Aviation Key Laboratory of Science and Technology on AISSS | Zhao T.,Beijing Institute of Technology | Zhao T.,Aviation Key Laboratory of Science and Technology on AISSS
IEEE Signal Processing Letters | Year: 2015

This letter considers waveform design of orthogonal frequency division multiplexing (OFDM) signal for radar applications, and aims at mitigating the envelope fluctuation in OFDM. A novel method is proposed to reduce the peak-to-mean envelope power ratio (PMEPR), which is commonly used to evaluate the fluctuation. The proposed method is based on the tone reservation approach, in which some bits or subcarriers of OFDM are allocated for decreasing PMEPR. We introduce the coefficient of variation of envelopes (CVE) as the cost function for waveform optimization, and develop an iterative least squares algorithm. Minimizing CVE leads to distinct PMEPR reduction, and it is guaranteed that the cost function monotonically decreases by applying the iterative algorithm. Simulations demonstrate that the envelope is significantly smoothed by the proposed method. © 2015 IEEE.


Zhao T.,Beijing Institute of Technology | Zhao T.,Aviation Key Laboratory of Science and Technology on AISSS | Huang T.,Beijing Institute of Technology | Huang T.,Aviation Key Laboratory of Science and Technology on AISSS
2015 IEEE Global Conference on Signal and Information Processing, GlobalSIP 2015 | Year: 2015

The Cramer-Rao Lower Bounds (CRLBs) of the joint time delay and Doppler stretch estimation for an extended target is derived in this paper. The results indicate that the CRLB of the Doppler stretch is inversely proportional to the effective time-bandwidth product of the transmitted signal. The estimator using wideband ambiguity function (WBAF) is evaluated for the extended target case through numerical experiments. Our results indicate that the WBAF estimator, which is derived under the single point scatterer assumption, is not appropriate to the parameter estimation for an extended target. © 2015 IEEE.


Zhu J.,Beijing Institute of Technology | Zhao T.,Beijing Institute of Technology | Huang T.,Beijing Institute of Technology | Zhang D.,Aviation Key Laboratory of Science and Technology on AISSS
2016 IEEE Radar Conference, RadarConf 2016 | Year: 2016

Random pulse repetition interval (PRI) waveform arouses great interests in the field of modern radars due to its ability to alleviate range and Doppler ambiguities as well as enhance electronic counter-countermeasures (ECCM) capabilities. Theoretical results pertaining to the statistical characteristics of ambiguity function (AF) are derived in this work, indicating that the range and Doppler ambiguities can be effectively suppressed by increasing the number of pulses and the range of PRI jitters. This provides an important guidance in terms of waveform design. As is well known, the significantly lifted sidelobe pedestal induced by PRI randomization will degrade the performance of weak target detection. Proceeding from that, we propose to employ orthogonal matching pursuit (OMP) to overcome this issue. Simulation results demonstrate that the OMP method can effectively lower the sidelobe pedestal of strong target and improve the performance of weak target estimation. © 2016 IEEE.


Huang T.,Beijing Institute of Technology | Huang T.,Aviation Key Laboratory of Science and Technology on AISSS | Zhao T.,Beijing Institute of Technology | Zhao T.,Aviation Key Laboratory of Science and Technology on AISSS
IET Conference Publications | Year: 2015

This paper considers waveform design of orthogonal frequency division multiplexing (OFDM) signal for radar applications, which aims at mitigating the envelope fluctuation in OFDM. A novel method is proposed to reduce the peak-to-mean envelope power ratio (PMEPR), which is commonly used to evaluate the fluctuation. The proposed method is based on the tone reservation approach, in which some bits or subcarriers of OFDM are allocated for decreasing PMEPR. We introduce the coefficient of variation of envelopes (CVE) as the cost function for waveform optimization, and develop an iterative least squares algorithm. Minimizing CVE leads to distinct PMEPR reduction, and it is guaranteed that the cost function monotonically decreases by applying the iterative algorithm. Simulations demonstrate that the envelope fluctuation is significantly smoothed by the proposed method.


Gao Y.,Beijing Institute of Technology | Gao Y.,Aviation Key Laboratory of Science and Technology on AISSS | Tian M.,Beijing Institute of Technology | Tian M.,Aviation Key Laboratory of Science and Technology on AISSS
IET Conference Publications | Year: 2015

Pulse tracking is extensively applied in sampling guidance for intra-pulse analysis, antenna scan analysis, special signal accurate orientation in electronic intelligence (ELINT), as well as in passive radar seeker (PRS). In some real-time application such as PRS system, existed tracking algorithm cannot deal with complex modulated pulse repetition interval (PRI) as wobulated PRI and linear sliding PRI. In this paper, a linear PRI predictor with adaptive weights is designed and applied, with which the proposed method achieves remarkable improvement compared to the existed algorithm. Experimental results verify the method can well deal with wobulated, linear sliding and stagger PRI modulation, and considerably improve the algorithm's resistance to bind error of PRI.


Yang X.,Beijing Institute of Technology | Yang X.,Aviation Key Laboratory of Science and Technology on AISSS | Gu H.,Beijing Institute of Technology | Gu H.,Aviation Key Laboratory of Science and Technology on AISSS
IET Conference Publications | Year: 2015

The de-interleave of pulse train with jittered pulse repetition interval (PRI) has been an intractable problem for decades. In this paper, we focus on jittered PRI detection using time difference of arrival (TDOA) histogram. An analytic expression of the detection threshold is derived. Moreover, parameter estimation methods for jittered PRI are proposed. The estimation is important for setting tolerance window length in TDOA histogram as well as for rejecting independent sequence after corresponding PRI is detected. Based on the detection threshold and parameter estimation, a de-interleaving procedure for jittered PRI pulse train is given. Simulation results demonstrate its advantages in the given s cenario.


Nie C.,Aviation Key Laboratory of Science and Technology on AISSS | Wang X.,Aviation Key Laboratory of Science and Technology on AISSS | Zhao H.,Aviation Key Laboratory of Science and Technology on AISSS
2013 5th IEEE International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, MAPE 2013 | Year: 2013

This paper describes the design of a 77 GHz transceiver, as the key component of the FMCW radar on airport runways, which requires a source with very low phase noise, a unique linear frequency modulation technique with high phase accuracy, a low-cost 77GHz T/R circuit with high performance. The transceiver consists of a frequency synthesizer including DDS and up-conversion, a T/R front-end including multiplier followed by PA and LNA followed by IQ down-conversion, a IF receiver including audio amplifiers, filters and so on. Some key performance parameters are as follows: transmitted power >400mW, overall noise figure <6.5 dB, a highly stable W-band source with phase noise ≤ - 100dBc/Hz@100kHz. The transceiver discussed in this paper has been working on the airport runway and showing its capability in the imaging application. © 2013 IEEE.

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