Design of LDMOS Power Amplifier Based on D-CRLH Bandpass Filter Matching Network

This paper proposes a design method for broadband power amplifiers based on bandpass filter matching networks. The approach incorporates transistor complex impedance transformation into the filter matching network design using a low-pass filter design model. By integrating CRLH and D-CRLH structural elements, it forms LC matching structures with a bandpass filter response. This structure achieves wide-band impedance transformation while also providing excellent frequency-selective capabilities. To validate this approach, a 0.7–1.3 GHz bandpass filtering power amplifier was designed and fabricated. It achieves in-band saturated output power of 38.4–41 dBm, drain efficiency of 41–58%, and power gain exceeding 12 dB. The gain flatness is limited to within ±2 dB. Experimental measurements validate the proposed design methodology. This approach imparts exceptional frequency selectivity and superior filtering performance to the system while enabling effective circuit miniaturization. Moreover, it exhibits considerable engineering significance and promising application potential in key fields such as satellite communications, radar monitoring, and digital broadcasting.