A driver amplifier with the configurable transformer-based matching network (CTMN) is proposed in this paper. By configuring the resistor arrays and capacitor arrays of the CTMN through a digital circuit, parameters such as the gain, the bandwidth, the gain flatness and the ripple of the matching network can be reconstructed, and the adverse effects of process fluctuations, layout parasitic effects and model deviations can be mitigated. In 65-nm CMOS technology, a driver amplifier with CTMNs is realized and integrated in a receiver. Experimental results show that with CTMNs, from 18.2 GHz to 20.2 GHz the S 22 can be improved by 3.5 dB, the S 21 can be improved by 0.5 dB, the gain flatness can be improved by 0.1 dB, and the -3 dB bandwidth can be improved by 113 MHz.