LAUSR

This Letter presents a new combination of a broadband power amplifier (PA) and an output microstrip hairpin bandpass filter. The filter is designed based on the fifth-order Chebyshev low-pass prototype element values. Even-odd mode impedance analysis is used to calculate the filter parameters. Meanwhile, only the fundamental impedance matching is considered for this design. Therefore, a highly selective bandpass response is obtained to provide a spurious-free fundamental impedance matching. For verification, a broadband PA-filter component across 1.9-3.1 GHz (48%) is designed and fabricated. Measurements have shown a drain efficiency of 48-56.6% with 39.3-40.5 dBm of maximum output power.