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Microstrip stepped‐impedance ring all‐pass filter and wideband 90° phase shifter
Author(s) -
Jin XiuHua,
Huang XiaoDong,
Cheng ChongHu
Publication year - 2014
Publication title -
international journal of rf and microwave computer‐aided engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.335
H-Index - 39
eISSN - 1099-047X
pISSN - 1096-4290
DOI - 10.1002/mmce.20748
Subject(s) - wideband , phase shift module , transmission line , microstrip , electrical impedance , linear phase , electronic engineering , low pass filter , nonlinear system , bandwidth (computing) , acoustics , microwave , equivalent circuit , characteristic impedance , filter (signal processing) , electrical engineering , materials science , engineering , insertion loss , physics , telecommunications , voltage , quantum mechanics
A new all‐pass filter (APF) is proposed. The APF is based on a symmetrical ring, consisting of four sections of transmission line, which are identical in electrical length, different in characteristic impedance. Two input/output ports are connected orthogonally to the ring. The APF is analyzed by using the odd‐even model, and the all‐pass condition is then theoretically obtained. Meeting the condition, the circuit is all‐pass in frequency, but nonlinear in transmission phase. The nonlinear transmission phase with frequency may be adjusted by changing the lines' impedances, while remaining the all‐pass property. Then the APF is used to design a wideband 90° differential phase shifter with adjustable bandwidth. Samples are designed, fabricated and measured. Good agreements are achieved among the theoretic, numerical and experimental results. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:191–195, 2014.