Abstract:
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 1.2
λ×0.96
λ@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 time-modulated module is miniaturized with good performances.