Size-Reduced and Broadband Ring Hybrid Coupler with Arbitrary Power Division using Phase Inverters

摘要

Novel compact rat-race hybrid-ring coupler with phase inverters of slot-line consisting of microstrip line hybrid ring and slot-line phase inverters are proposed. The features and design criteria of broad-band reverse-phase hybrid ring couplers are presented. Effective bandwidth of a new reverse-phase hybrid ring coupler can be increased by 46% with a return loss of 12dB. In addition, we present a class of microstrip phase inverters and discuss their technical aspects. Experimental results show that the bandwidth of the proposed phase inverter is greater than 100% with insertion loss below 1 dB and phase shift error of less than ± 7°. Measurements confirm that the new microstrip-line hybrid ring coupler provides attractive features. Its isolation is better than 20 dB over a 45% bandwidth attributed to the phase inverter providing almost a 100% bandwidth.