Dual-Band Techniques in A 79/135 GHz Power Amplifier in 28nm Bulk CMOS

This paper explores mmWave-frequency dualband matching techniques, which are demonstrated in a dualband 3-stage Power Amplifier (PA) that operates in both E-band and D-band. A coupled-resonator concept is applied in order to provide sufficient tuning ratio and consequently allows multiband operation. Active components and passive structures are co-designed to optimize the performance for both bands. The PA has been implemented in 28 nm bulk CMOS and characterized using on-wafer probing. At the operating frequency of 79 GHz, it provides 23 dB power gain, 8.7 dBm output <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1-\text{dB}$</tex> compression point <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathbf{P}_{\mathbf{1 d B}})$</tex>, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1 1. 1 d B m}$</tex> saturated output power <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathbf{P}_{\text{sat }})$</tex> with a peak power added efficiency (PAEmax) of 12.4%. At 135 GHz, the measured power gain is 11.5 dB, achieved <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{P}_{1 \text{dB}}$</tex> is 3.9 dBm. <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{P}_{\text{sat }}$</tex> is 9.4 dBm with PAE <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$_{\text{max }}$</tex> of 5.9%. The proposed techniques appear to be cost effective.