The Study and Design of the Stability of RF Power Amplifier

The RF Power Amplifier is an important component, whose stability can greatly affect the reliability of the communication system. Based on the self-designed RF-LDMOS device, a RF power amplifier was designed by ADS and its stability was studied. The R-C parallel circuit was added in the gate to improve the stability of the power amplifier in the 100MHz-200MHz band. Experience shows that the R-C parallel circuit performed as resistance when the frequency was under the transition frequency and performed as capacitance to the contrary. As a result, the R-C parallel circuit can effectively reduce the gain in low frequency with having no influence in the working frequency. The improved power amplifier has a stable gain of more than 17.4 dB in the 100 MHz-200 MHz band, and the output power of over 37.4 dBm.