Optimum Reflection-Type Phase Shifter Using (Ba,Sr)TiO3 Thin Film
Authors: Kim Y-T.1; Ryu H-C.2; Kwak M-H.2; Moon S-E.2; Lee S-J.2; Kim S-H.1; Park J-S.3; Han S-K.4
Source: Integrated Ferroelectrics, Volume 56, Number 1, Volume 56/2003 , pp. 1107-1114(8)
Publisher: Taylor and Francis Ltd
Abstract:
In this paper, in order to obtain a large differential phase shift with a little change in applied voltage, a ferroelectric reflective load circuit has been designed on top of barium strontium titanate (Ba,Sr)TiO3 [BST] thin film. The design of the ferroelectric reflection-type phase shifter is based on a reflection theory of terminating circuit, which has a reflection-type analogue phase shifter with two ports terminated in symmetric phase-controllable reflective networks. To achieve large amounts of phase shift in low bias-voltage range, the effects of change of capacitance and transmission line connected with two coupled ports of a 3-dB 90° branch-line hybrid coupler have been investigated. A large phase shift with a small capacitance change in the parallel terminating circuit has been demonstrated in the paper.Keywords: Reflection-type phase shifter; ferroelectric reflective circuit; (Ba, Sr) TiO3 thin films; BST interdigital capacitor
Document Type: Research article
Affiliations: 1: Division of Information Technology Engineering, Soonchunhyang University 2: Basic Research Laboratory, Electronics and Telecommunications 3: School of Electric Engineering, Kookmin University 4: RF-tron Co. Ltd

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