We demonstrate a high-resolution frequency-modulated continuous-wave dual-frequency LIDAR system based on a monolithic integrated two-section(TS) distributed feedback(DFB) laser. In order to achieve phase locking of t...We demonstrate a high-resolution frequency-modulated continuous-wave dual-frequency LIDAR system based on a monolithic integrated two-section(TS) distributed feedback(DFB) laser. In order to achieve phase locking of the two lasers in the TS-DFB laser, the sideband optical injection locking technique is employed. A high-quality linear frequency-modulated signal is achieved from the TS-DFB laser. Utilizing the proposed LIDAR system, the distance and velocity of a target can be measured accurately. The maximum relative errors of distance and velocity measurement are 1.6% and 3.18%, respectively.展开更多
To determine the feasibility and practicability of interrupt continuous wave (CW) approach proposed for real time simulating radar intermediate frequency(IF) video signal, theoretical analysis and computer simulation...To determine the feasibility and practicability of interrupt continuous wave (CW) approach proposed for real time simulating radar intermediate frequency(IF) video signal, theoretical analysis and computer simulation were used. Phases at two linked points between the end and beginning of adjoined frames are always consistent; the bias Doppler frequency for the time delay of A/D sampling start responds to that for target acceleration. No digital phase compensation is required at continuous points, and the interrupt CW approach has apparently practical values.展开更多
The influence of frequency modulation （FM） interfer- ence on correlation detection performance of the pseudo random code continuous wave （PRC-CW） radar is analyzed. It is found that the correlation output deterior...The influence of frequency modulation （FM） interfer- ence on correlation detection performance of the pseudo random code continuous wave （PRC-CW） radar is analyzed. It is found that the correlation output deteriorates greatly when the FM inter- ference power exceeds the anti-jamming limit of the radar. Accord- ing to the fact that the PRC-CW radar echo is a wideband pseudo random signal occupying the whole TF plane, while the FM in- terference only concentrates in a small portion, a new method is proposed based on adaptive short-time Fourier transform （STFT） and time-varying filtering for FM interference suppression. This method filters the received signal by using a binary mask to excise only the portion of the TF plane corrupted by the interference. Two types of interference, linear FM （LFM） and sinusoidal FM （SFM）, under different signal-to-jamming ratio （S JR） are studied. It is shown that the proposed method can effectively suppress the FM interference and improve the performance of target detection.展开更多
The formula for calculating the threshold of average transmitting power of cylindrical TE11 mode window is revised by accurate deduction and a practical method for calculating the temperature increment of the dielectr...The formula for calculating the threshold of average transmitting power of cylindrical TE11 mode window is revised by accurate deduction and a practical method for calculating the temperature increment of the dielectric disk in cylindrical box type window is given. Meanwhile,a typical cylindrical box type window is calculated and used as an example to discuss the power capacity, the special harmfulness and elimination of ghost mode resonance when the window is used to transmit high power Continuous Wave(CW).展开更多
基于0.25μm Ga N HEMT工艺,研制了一款S波段Ga N功率放大器单片微波集成电路（MMIC）。该电路采用三级拓扑放大结构,提高了放大器的增益;采用电抗匹配方式,减小了电路输出级的损耗,提高了MMIC的功率和效率。输出级有源器件的布局优化,...基于0.25μm Ga N HEMT工艺,研制了一款S波段Ga N功率放大器单片微波集成电路（MMIC）。该电路采用三级拓扑放大结构,提高了放大器的增益;采用电抗匹配方式,减小了电路输出级的损耗,提高了MMIC的功率和效率。输出级有源器件的布局优化,改善了放大器芯片的温度分布特性。测试结果表明,在2.8~3.6 GHz测试频带内,在脉冲偏压28 V（脉宽100μs,占空比10%）时,峰值输出功率大于60W,功率附加效率大于45%,小信号增益大于34 d B,增益平坦度在±0.3 d B以内,输入电压驻波比在1.7以下;在稳态偏压28 V时,连续波饱和输出功率大于40 W,功率附加效率38%以上。该MMIC尺寸为4.2 mm×4.0 mm。展开更多
基金This work was supported in part by the National Key R&D Program of China(No.2018YFA0704402)National Natural Science Foundation of China(Nos.61974165 and 61975075)+1 种基金National Natural Science Foundation of China for the Youth(No.62004105)Science and Technology Project,and Natural Science Foundation of Jiangsu Province(No.BE2019101)。
文摘We demonstrate a high-resolution frequency-modulated continuous-wave dual-frequency LIDAR system based on a monolithic integrated two-section(TS) distributed feedback(DFB) laser. In order to achieve phase locking of the two lasers in the TS-DFB laser, the sideband optical injection locking technique is employed. A high-quality linear frequency-modulated signal is achieved from the TS-DFB laser. Utilizing the proposed LIDAR system, the distance and velocity of a target can be measured accurately. The maximum relative errors of distance and velocity measurement are 1.6% and 3.18%, respectively.
文摘To determine the feasibility and practicability of interrupt continuous wave (CW) approach proposed for real time simulating radar intermediate frequency(IF) video signal, theoretical analysis and computer simulation were used. Phases at two linked points between the end and beginning of adjoined frames are always consistent; the bias Doppler frequency for the time delay of A/D sampling start responds to that for target acceleration. No digital phase compensation is required at continuous points, and the interrupt CW approach has apparently practical values.
文摘The influence of frequency modulation （FM） interfer- ence on correlation detection performance of the pseudo random code continuous wave （PRC-CW） radar is analyzed. It is found that the correlation output deteriorates greatly when the FM inter- ference power exceeds the anti-jamming limit of the radar. Accord- ing to the fact that the PRC-CW radar echo is a wideband pseudo random signal occupying the whole TF plane, while the FM in- terference only concentrates in a small portion, a new method is proposed based on adaptive short-time Fourier transform （STFT） and time-varying filtering for FM interference suppression. This method filters the received signal by using a binary mask to excise only the portion of the TF plane corrupted by the interference. Two types of interference, linear FM （LFM） and sinusoidal FM （SFM）, under different signal-to-jamming ratio （S JR） are studied. It is shown that the proposed method can effectively suppress the FM interference and improve the performance of target detection.
文摘The formula for calculating the threshold of average transmitting power of cylindrical TE11 mode window is revised by accurate deduction and a practical method for calculating the temperature increment of the dielectric disk in cylindrical box type window is given. Meanwhile,a typical cylindrical box type window is calculated and used as an example to discuss the power capacity, the special harmfulness and elimination of ghost mode resonance when the window is used to transmit high power Continuous Wave(CW).
文摘基于0.25μm Ga N HEMT工艺,研制了一款S波段Ga N功率放大器单片微波集成电路（MMIC）。该电路采用三级拓扑放大结构,提高了放大器的增益;采用电抗匹配方式,减小了电路输出级的损耗,提高了MMIC的功率和效率。输出级有源器件的布局优化,改善了放大器芯片的温度分布特性。测试结果表明,在2.8~3.6 GHz测试频带内,在脉冲偏压28 V（脉宽100μs,占空比10%）时,峰值输出功率大于60W,功率附加效率大于45%,小信号增益大于34 d B,增益平坦度在±0.3 d B以内,输入电压驻波比在1.7以下;在稳态偏压28 V时,连续波饱和输出功率大于40 W,功率附加效率38%以上。该MMIC尺寸为4.2 mm×4.0 mm。
