Miniature 60 GHz CMOS dual balun with excellent amplitude and phase properties

作者：Lin Yo Sheng^*; Lin Yun Wen

来源：Electronics Letters, 2016, 52(4): 295-U83.

DOI：10.1049/el.2015.3520

• baluns
• CMOS integrated circuits
• millimetre wave integrated circuits
• impedance matching
• power dividers
• frequency 50 GHz to 110 GHz
• miniature CMOS dual balun
• phase properties
• amplitude properties
• star mixer
• power amplifier
• four-way equal power dividing
• two-fold metal
• coupling coefficient
• input-port impedance matching
• output-port transmission properties
• magnitude of amplitude imbalance
• MAI
• PD
• phase difference
• millimetre-wave systems

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 approximate to-7.9 dB, S-31 of -7.9 approximate to-9 dB, S-41 of -7.5 approximate to-7.9 dB, S-51 of -7.8 approximate to-8.9 dB, magnitude of amplitude imbalance (MAI) of 0.34-1.1 dB and phase difference (PD) of 179.22 degrees-180.78 degrees for ports 2-3 and MAI of 0.3-1 dB and PD of 178.83 degrees-180.48 degrees for ports 4-5. The state-of-the-art results of the dual balun indicate that it is suitable for millimetre-wave systems.

• 出版日期2016-2-18