A Study on the Miniaturization of 3-dB Ring Hybrid Having Arbitrary Termination Impedance Using Lumped-Equivalent Circuit

임의의 종단 임피던스를 갖는 3-dB 원형 하이브리드의 집중소자 등가회로를 이용한 소형화에 관한 연구

In UHF, VHF new design method of samll-sized 3-dB 0$^{\circ}$/180$^{\circ}$ ring hybrid terminated arbitrary impedance using both lumped elements and distributed elements is presented. At the center frequency of 900 MHz, 3-dB 0$^{\circ}$/180$^{\circ}$ ring hybrid terminated arbitrary impedance is designed, analyzed and tested. Good agreements are obtained between measured and theoretical modeling results, and at the same time, the circuit area of hybrid fabricated with two dimensional parallel coupled line, distributed elements and lumped elements is reduced by more than 70% compared with only distribyted-type circuits.