基于2比特结构的时间调制模块小型化设计

The miniaturized design of time module based on 2-bit structure

针对时间调制阵列中调制模块的小型化问题,采用多层板结构,将模块中开关的谐振单元和偏置电路以及射频信号电路放置在不同层,并通过类同轴耦合线和缺陷地等不同的技术措施结合,解决了不同射频通道之间的幅相不平衡以及谐振等问题,在实现小型化的同时兼顾了电性能.据此设计了2比特结构的时间调制模块,该模块工作频段为14.2~16.4 GHz,尺寸为1.2λ×0.96λ@15.3 GHz,相邻状态相移为90°±5°,幅度差为±0.5 dB.在载波频率为15.3 GHz、调制频率为1 MHz时可达到34 dB谐波抑制,最大信号带宽则可达200 MHz,验证了本文设计方法的有效性.

Aiming at the miniaturization of the module in the time-modulated array,the multi-layer structure is adopted.Different parts such as the resonant unit,the bias circuit of the switch and the RF signal circuit are placed on different layers in the module.By using several structures such as coaxial-like coupling line and defective ground,the imbalance problems of amplitude and phase between different branches and resonance phenomena in the module are improved.A time-modulated module with a miniaturized 2-bit structure is designed,which is operating between 14.2 and 16.4 GHz and the size is 1.2λ×0.96λ@15.3 GHz with a phase shift within 90°±5°and an amplitude difference within±0.5 dB between adjacent state.The module has achieved the harmonic suppression of 34 dB at carrier frequency of 15.3 GHz and modulation frequency of 1 MHz and the maximum signal bandwidth of 200 MHz.Thus a 2-bit timemodulated module is miniaturized with good performances.