A compact DC-to-82.4-GHz amplifier using 0.15 μm pHEMT process is demonstrated in this paper. The amplifier is implemented in common-source (CS) configuration with bandwidth extension technique. The frequency response and input and output impedances of the amplifier are investigated to obtain the design methodology. The amplifier exhibits a high gain-bandwidth product (GBP) of 328 GHz with a chip size of 0.7 × 1 mm2. Moreover, the amplifier is evaluated using pseudorandom bit stream (PRBS) signal with a data rate up to 12 Gbps. The proposed amplifier has potential for the high-speed data rate transmission due to its superior performance.