光导微波源阵列合成时控技术初步研究

Primary study on time control technology of active phased arraybased on photoconductive microwave source

基于宽禁带光导半导体的固态光导微波源是高功率微波产生的一种新途径,该方案具有功率密度高、频带范围宽等特点,且其低时间抖动特性使其在功率合成方面具有巨大潜力,利用光波束形成网络构建光导微波有源相控阵是光导微波器件迈向实用的重要途径。分析了光导微波相控阵系统原理,设计了光导微波真延时网络架构,并构建了差分真延时相控阵和考虑相位随机误差的真延时相控阵的理论模型,对影响功率合成和波束扫描的关键因素开展定量分析和仿真验证。结果表明,对于发射1 GHz信号的n×10阵列,延时均方差在10 ps以下时,指向偏差小于0.13°,峰值增益损耗小于2%;延时步进精度在10 ps以下时,指向偏差小于0.2°,峰值增益损耗小于0.03%。由此提出延时精度指标,为未来更高功率、更大规模的光导微波合成技术发展提供参考。

Solid-state photoconductive microwave source based on wide-bandgap photoconductivesemiconductor is a new way of high power microwave generation.The scheme has the characteristics of high powerdensity and wide frequency band,and its low time jitter characteristic makes it have great potential in power synthesis.The construction of active phased array of photoconductive microwave devices using optical beamforming network isan important way for the application of photoconductive microwave devices.In this paper,the principle of opticalmicrowave phased array system is analyzed,and the theoretical models of differential true delay phased array and truedelay phased array considering phase random error are constructed.The key factors affecting power synthesis andbeam scanning are quantitatively analyzed and simulated,and the delay precision index is proposed.The results showthat for the n×10 array transmitting signal at 1 GHz,when the delay phase variance is less than 10 ps,the pointingdeviation is less than 0.2°and the peak gain loss is less than 2%.When the delay step accuracy is less than 10 ps,thepointing deviation is less than 0.2°,and the peak gain loss is less than 0.03%.On this basis,the real time delaynetwork architecture of photoconductive microwave is designed,which provides a reference for the development ofhigher power and larger scale photoconductive microwave synthesis technology in the future.