Open AccessCoupled‐line directional coupler with tunable power division ratio and operating frequency
Author(s) -
Shen Xiaochuan,
Liu Yuanan,
Zhou Siyue,
Wu Yongle
Publication year - 2017
Publication title -
iet microwaves, antennas and propagation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.555
H-Index - 69
eISSN - 1751-8733
pISSN - 1751-8725
DOI - 10.1049/iet-map.2016.0067
Subject(s) - power dividers and directional couplers , planar , microstrip , division (mathematics) , power (physics) , materials science , coupling (piping) , line (geometry) , electronic engineering , electrical engineering , engineering , physics , computer science , mathematics , computer graphics (images) , arithmetic , geometry , quantum mechanics , metallurgy
This study presents a novel planar coupled‐line directional coupler with tunable both power division ratio and operating frequency, which is achieved using microstrip technology for the first time. Its tunability of the operating frequency and the power division ratio, or coupling ratio, can be independently controlled by the bias voltages. Moreover, it can simultaneously maintain perfect port match and isolation. On the basis of the even–odd mode analysis method, both the closed‐form analytical equations and parameter discussions are provided to facilitate the practical design. An experimental prototype of the tunable coupler is simulated, fabricated, and measured to demonstrate how it works. The measured results indicate that power division ratio can vary from 0.35 (9 dB) to 0.71 (3 dB) when operating frequency ranges from 0.55 to 1.48 GHz (91.63%) while power division ratio varies from 0.35 (9 dB) to 1 (0 dB) when operating frequency is fixed at 1 GHz, which validated the reliability of the proposed model.