Design Of GaN Power Amplifier Based On Novel Matching Circuit Structure

Power amplifier is an important part of the wireless communications.High power,miniaturized,and high efficiency power amplifiers have become the popular research direction in the present.By improving the matching structure circuit of power amplifiers,the output power and efficiency can be greatly improved,and the integration degree can also be improved.Compared with Ga As devices,GaN power amplifiers have higher breakdown voltage,larger power capacity,higher output power and more suitable for high frequency and high temperature,so it has gradually become popular in the high-efficiency power amplifier design.This paper focuses on the GaN power amplifier with the new matching structure circuit.The main work is as follows:1.High power combining amplifier: Based on the synthesis of power combining technology,a RF power combining amplifier is designed.Firstly the class AB power amplifier and the power divider are designed respectively,then the matching circuit between the power divider and power amplifier is analyzed and designed in detail,so the design realizes the direct cascade of power divider,power amplifier and power combiner and improves the circuit integration.Finally the output power is doubled,and the linearity of circuit is also improved.2.A Class-F power amplifier based on harmonic control network: By analyzing the synthesis of class F power amplifier,the harmonic control network is added to the output matching circuit,so as to meet the impedance characteristics of class F power amplifier that the odd harmonics are open,even harmonics are short,and at the same time the fundamental one is matched to the 50 ? load impedance.This improves the output power and efficiency of the amplifier greatly.Finally,the design circuit is processed and tested,and the results meet the requirements.3.A Class-F filtering power amplifier based on SIW technology: Based on the concept of microwave device function fusion,a class F power amplifier based on SIW filter is introduced.By adjusting the input impedance of the SIW double-cavity filter to a complex impedance,which is the optimal load impedance of the power amplifier,the direct cascade between the filter and the power amplifier is realized,reducing the circuit complexity and is more suitable for the work of high frequency.Meanwhile,the harmonic control network is employed,controlling the second and third harmonics effectively and improving the efficiency of the filtering power amplifier greatly.