小型化超宽带3 dB定向耦合器设计

Design of Miniaturized Ultra-Wideband 3 dB Directional Coupler

设计并实现了一个小型化超宽带3 dB定向耦合器,采用对称多节耦合带状线的形式,由一个十七阶耦合器和一个五阶耦合器交叉串联构成,并通过采用弯折线,缩减了整体尺寸,可实现13:1倍频程的工作带宽。测试结果表明,在0.2~2.65 GHz频率范围内,电压驻波比小于1.35,隔离度小于-17 dB,带内波动为-3.4±0.6 dB,能够实现90°相移。

A miniaturized ultra-wideband 3 dB directional coupler working in 0.2~2.65 GHz is presented,which adopts symmetrical multi-section coupling strip line.The coupler is composed of a seventeen-section coupler and a five-section coupler in cross series.By using meander lines,it achieves a compact size with 13:1 bandwidth.The measured results show that the Voltage Standing Wave Ratio(VSWR)is less than 1.35 within the bandwidth covering 0.2~2.65 GHz,the isolation is less than-17 dB,the in-band ripple is within-3.4±0.6 dB,and 90°phase shift can be achieved.