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A novel frequency‐tunable branch line coupler
Author(s) -
Liao ZhenHeng,
Zhang XuChun,
Yang Xiao
Publication year - 2018
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.21154
Subject(s) - hybrid coupler , return loss , wideband , frequency band , line (geometry) , resistor , phase (matter) , capacitor , electrical engineering , voltage , materials science , power dividers and directional couplers , physics , engineering , mathematics , geometry , quantum mechanics , antenna (radio)
This article introduces a novel two‐section frequency‐tunable branch line coupler, which is realized by inserting a narrow band frequency‐tunable phase inverter into a wideband two‐section branch line coupler's middle branch line. Such frequency‐tunable method is different from the conventional one. Furthermore, in this bias feeding design, there are only one control voltage, two varactors, two resistors, and two capacitors are utilized. The measured results show that the operation frequency of the branch line coupler can be tuned from 0.73 to 1.33 GHz, and the return loss is >20 dB, the isolation >20 dB, the amplitude imbalances <1 dB, and the phase imbalances is <2°. Through the comparison, the measured results basically conform to the simulated results in this design.