A Ku-band power amplifier (PA) with T-model matching network is implemented using 0.25 μm GaN pHEMT process in this paper. To achieve broadband with high output power, the output matching of the PA is realized using the T-model matching network. Between 12 and 17 GHz, the small-signal gain and saturation output power (Psat) are higher than 12 dB and 29 dBm, resepectively. The measured maximum small-signal gain is 12 dB as the frequency is 16 GHz. When the supply voltage is 25 V, the proposed PA demonstrated a Psat of 27 dBm over the frequency, and a maximum power-added efficiency (PAE) of higher than 8% at 15 GHz.