A broadband millimeter-wave (mmWave) power amplifier (PA) was implemented using a modified 2D distributed power combining technique. The proposed power combining was based on a single-ended dual-fed distributed combining (SEDFDC) design technique using zero-phase shifting (ZPS) transmission lines. To improve the input/output power distribution of each power cell within a wide frequency range, N/2-way power dividers/combiners were inserted into the distributed combining structure. Modified ZPS lines also simplified the combining structure and curbed phase variation according to the frequency. These modifications enabled power combining cells to increase without degrading the power bandwidth. The proposed PA was fabricated with a commercial 0.15 μm GaAs pseudo high electron-mobility transistor (pHEMT) monolithic microwave-integrated circuit (MMIC) process. It exhibited 20.3 to 24.2 dBm output power (Pout), 12.9 to 21.8 dB power gain, and 5.2% to 12.7% power-added efficiency (PAE) between 26 and 56 GHz.
A 2-D Distributed Power Combining by Metamaterial-Based Zero Phase Shifter for 60-GHz Power Amplifier in 65-nm CMOS
