Design And Fabrication Of L-band Balanced Power Amplifier

With the rapid progress of wireless communication, data communication andspace communication, RF PA is widely used in mobile communication system, digitaltransmitter and military affairs technology field, as one of the most importantcomponents in RF system. To meet new requirements and challenges, RF PA shouldhave large bandwidth，high output power，high efficiency and good linearity，so it issignificant for the further studies on PA.Some theories of PA were discussed in this paper at first, such as two-portnetworks, transistor stability, designing of matching networks and so on. Design of PAin ADS was also illustrated. By using the method of academic research and simulationin ADS, a three-stage L-band balanced power amplifier with large output power, highcombining-efficiency and high PAE was presented. The input and output impendenceof power transistor were achieved through the load-pull designing method to realizethe conjugated matching in ADS.A3dB Branch Line Hybrid Coupler was employed tosplit and combine the signal. From the measured results, the P-1was42.73dBm withthe power gain over60dB at1.5GHz, the combining efficiency of93%and the PAE of48.7%was achieved as well. The influences which caused by insertion loss, amplitudeunbalance and phase unbalance which generated by power amplifiers were investigatedboth through simulation method and measurement. As a consequence，the influencescaused by phase unbalance was more obvious than amplitude unbalance.