Open AccessSimple ladder‐like single‐layer balanced wideband phase shifter with wide phase shift range and appropriate common‐mode suppression
Author(s) -
Karim Alizadeh Mohammad,
Shamsi Hossein,
Bagher Tavakoli Mohammad,
Aliakbarian Hadi
Publication year - 2020
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.2020.0221
Subject(s) - phase shift module , insertion loss , wideband , return loss , phase (matter) , common mode signal , materials science , differential phase , bandwidth (computing) , electronic engineering , optoelectronics , electrical engineering , telecommunications , physics , engineering , quantum mechanics , digital signal processing , analog signal , antenna (radio)
In this study, a single‐layer balanced wideband phase shifter with a wide phase shift range of 45°–315° and acceptable common‐mode (CM) suppression is proposed. The main branch has a simple ladder‐like structure and the reference branch utilises a coupling structure. The main branch electrical length is constant for any desired differential‐mode (DM) phase shift. Assuming a specific return loss (e.g. 16, 20, and 25 dB), the phase shifter is carefully analysed and a design procedure is given leading to an ultra‐low phase error design. Then by making a trade‐off between the CM and DM bandwidths at the cost of higher phase error, more design solutions for the phase shifter are given. To validate both the proposed structure as well as its design procedure, a balanced wideband phase shifter with the DM phase shift of 180°±4.2° (1.851–4.017 GHz) and the CM suppression of better than 15 dB (1.81–4 GHz) is fabricated, resulting in 73.82 and 75.25% fractional bandwidth, respectively. The fabricated balanced phase shifter has a return loss ofS 11dd< − 14.87dB and insertion loss ofS 21dd> − 0.95dB . The synthesised, simulated, and measured results are in good agreement with each other.