Power Amplifier Study And Realization Of 20W Wide Band And High Linearity From 70MHz To 300MHz

For modern microwave wireless communication,information transmission is being developed towards wide band,multi-carrier,large capacity and high speed rapidly,therefore,communication system raised higher requirements to bandwidth and linearity of RF modules,and especially for power amplifier whose bandwidth and linearity affect system performances and indexes directly.A wideband linear power amplifier of 20W by VHF(70-300MHz)band is developed which is decrypted in the paper.The main contents are listed following:1 General design of wide band linear power amplifier is performed.Using Advanced Design System(ADS)simulation software and engineer experience,amplifier simulation and parts index distribution are achieved.2 Performing parts design,facture and test,which include design of power amplifier matching circuit,bias circuit,control circuit.3 Fulfilling amplifier linearization design.In order to achieve linear indexes of the wideband amplifier,wideband matching techniques of loss matching and shunt feedback are adopted,and linearization techniques of power de-rating and feedback are adopted.4 Debugging and test are performed.The test results indicate that the power amplifier has following characteristics,such as wide operation band,low ripple in band,high linearity,great output power,and the indexes meet the anticipative goals.