A Broadband PA With Complementary Matching to Get High Impedance Transformation Ratio of 125 With 60% Bandwidth on Two-Layer HBT Process

This letter presents a two-stage broadband power amplifier (BPA) employing a complementary matching technique with a vertically coupling transformer (VCT) and a capacitor–capacitor transformer (CCT). The design achieves an ultrahigh impedance transformation ratio (ITR) of 125 at inter-stage, enabling effective matching over a relative bandwidth (RBW) exceeding 60%. Measured results show the fabricated PA delivers a saturated output power of 31.9–33.5 dBm and a gain of 26–30 dB with PAE of 41.6%–50% across 1.5–2.8 GHz.