Two-way Concurrent Dual-Band Power Amplifier at 0.9/1.8 GHz with Low Second Harmonic and Intermodulation

A novel two-way prototype which can suppress the second harmonic is proposed for concurrent dual-band power amplifier (PA). Each way with two filters makes it only operate in a band so that the harmonics can be filtered well and the intermodulation components of the two frequencies will not be generated. A 0.9/1.8 GHz dual-band PA is designed and fabricated. Measurement results show that the ratio of fundamental to second harmonic power are respectively -44.5 dBc and -41.5 dBc, and the intermodulation components are as low as noise. The output power of both bands is 41.0 dBm, and efficiency is 73.0%, while the corresponding gain are respectively 15.5 dB and 17.5 dB, under concurrent mode. The PA is stimulated with a concurrent 20-MHz wide-band signal, the ACPR are -34.5 dBc and -32.0 dBc with average power of 35 dBm, respectively.