Abstract
A 24-GHz balanced amplifier (BA) with a 45-dB gain is realized in 0.18-μm CMOS technology. An effective technique, π-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 × 0.63 mm 2 (core area: 0.78 × 0.43 mm 2 ) among the published narrowband amplifiers with similar technologies and operation frequencies. © 2008 IEEE.