Open AccessMiniature 60 GHz CMOS dual balun with excellent amplitude and phase properties
Author(s) -
Lin YoSheng,
Lin YunWen
Publication year - 2016
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2015.3520
Subject(s) - balun , impedance matching , electrical engineering , cmos , amplitude , transmission line , physics , amplifier , electrical impedance , materials science , optoelectronics , optics , antenna (radio) , engineering
A miniature CMOS dual balun which can be applied to a star mixer or a power amplifier for four‐way equal power dividing is reported. Compared with the four output coupled lines, the input coupled line has two‐fold metal width to achieve ideal coupling coefficient of 0.408. This is the way to achieve nearly perfect input‐port impedance matching and output‐port transmission properties. The dual balun occupies a small chip area of 0.0252 mm 2 and achieves S 11 smaller than −12 dB for frequencies of 50–110 GHz. For frequencies of 55–65 GHz, the dual balun achieves excellent S 21 of −7.6∼−7.9 dB, S 31 of −7.9∼−9 dB, S 41 of −7.5∼−7.9 dB, S 51 of −7.8∼−8.9 dB, magnitude of amplitude imbalance (MAI) of 0.34–1.1 dB and phase difference (PD) of 179.22°–180.78° for ports 2–3 and MAI of 0.3–1 dB and PD of 178.83°–180.48° for ports 4–5. The state‐of‐the‐art results of the dual balun indicate that it is suitable for millimetre‐wave systems.