任意耦合度集总宽带正交定向耦合器的研究

Analysis of Arbitrary-Coupling Broad Band Lumped-Element Quadrature Coupler

本文提出了一种任意耦合度集总宽带正交定向耦合器的分析及设计方法。本文首先从定向耦合器的奇偶模阻抗理论分析出发,得到任意耦合度定向耦合器单元的解算公式,然后通过级联单元定向耦合器得到任意耦合度集总宽带定向耦合器的元件解算公式。经ADS仿真验证,由解算公式得到的网络其耦合度值与计算结果相一致,级联起来的带宽也比单元定向耦合器的带宽要宽很多。为了进一步验证,本文结尾给出了一个中心频率为445MHz,耦合度值为5dB的设计实例,测试结果与仿真结果非常吻合。该耦合器有小尺寸,带宽大等优点。

This article presents an analysis and design method for the arbitrary-coupling broad band lumped-element quadrature coupler.It starts from the odd-even mode impedance analysis of the directional coupler,a solution of arbitrary-coupling directional unit coupler is obtained and then the design formulas for arbitrary-coupling broad band lumped-element quadrature coupler is derived from cascading two directional unit coupler.The simulation results of ADS coincide with the calculation results and the cascade coupler's bandwidth is much wider than the unit coupler.In order to further verify this method,a 5dB coupling with the center frequency of 445MHz is designed and fabricated.The measurement and simulation results closely correspond to each other.This coupler has advantages of small size,large bandwidth,and so on.