A 0.18-$\mu{\hbox {m}}$ CMOS Balanced Amplifier for 24-GHz Applications

A 24-GHz balanced amplifier (BA) with a 45-dB gain is realized in 0.18-mum CMOS technology. An effective technique, pi-type parallel resonance, is proposed to boost the high-frequency gain of a MOSFET by resonating out the inherent capacitances. The miniaturized lumped-element coupler in the circuit occupies a chip area of only ~2% compared to that of the conventional transmission-line coupler. The BA consumes 123 mW from a supply voltage of 1 V. To the best of the authors' knowledge, the proposed CMOS BA presents the highest gain of 45.0 dB with a chip area of 0.97 times 0.63 mm
²
(core area: 0.78 times 0.43 mm
²
) among the published narrowband amplifiers with similar technologies and operation frequencies.