Design and Fabrication of Distributed Analog Phase Shifter Using Ferroelectric (Ba,Sr)TiO$_3$ Thin Films

강유전체 (Ba,Sr)TiO$_3$ 박막을 이용한 분포 정수형 아날로그 위상변위기 설계 및 제작

This paper describes the design and fabrication of distributed analog phase shifter circuit. The phase shifter consist of coplanar waveguide(CPW) lines that are periodically loaded with voltage tunable (Ba,Sr)TiO$_3$ thin film interdigital(IDT) capacitors deposited by the pulsed laser deposition(PLD) on (001) MgO single crystals. The phase velocity on these IDT loaded CPW lines is a function of applied bias voltage, thus resulting in analog phase shifting circuits. The measured differential phase shift is 48$^{\circ}$ and the insertion loss decreases from -5㏈ to -3㏈ with increasing bias voltage from 0 to 40 V at 100㎐.