Open AccessFully dielectric interference‐based SPDT with liquid crystal phase shifters
Author(s) -
Jost Matthias,
Reese Roland,
Nickel Matthias,
Maune Holger,
Jakoby Rolf
Publication year - 2018
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.2017.0695
Subject(s) - phase shift module , materials science , insertion loss , port (circuit theory) , interference (communication) , dielectric , phase (matter) , optoelectronics , frequency band , transmission line , optics , electrical engineering , physics , topology (electrical circuits) , engineering , channel (broadcasting) , quantum mechanics , antenna (radio)
This study presents the first continuously tuneable, interference‐based W‐band single‐pole double‐throw (SPDT), fully implemented in subwavelength (sWL) dielectric fibre topology. Key components are the phase shifters in the two branches of the SPDT, which are realised as line sections filled with liquid crystal. They allow not only to adjust the signal ratios at the two output ports but also to tune the operating frequency between 93 and 110 GHz with isolation >25 dB. The first proof‐of‐concept SPDT demonstrator is realised and characterised at W‐band. However, concept and technology are scalable to higher frequencies. The complete SPDT with the WR10‐to‐sWL fibre transitions exhibits an insertion loss (IL) at the thru‐port between 5 and 7 dB in the frequency range from 85 to 110 GHz, where back‐to‐back measurements of the transitions itself already indicate an IL of up to 1.6 dB. The measurements at the isolated port of the SPDT exhibit transmission coefficients of less than −25 dB between 93 and 110 GHz with a minimum of −40 dB.