Research On 2-6GHz Broadband Balanced Internally Matched Power Amplifier

With the development of communication technology,the demand for long-distance communication is more and more high.As the most important part of transmitter,power amplifier objectively promotes the development of power amplifier.After several generations of technology updating and accumulating,solid-state power amplifier has attracted more and more researchers' attention under the advantage of high power and small volume.In particular,the third generation GaN high electron mobility transistor has a higher voltage withstand value than the previous two generations of technology,and high heat conduction,which is conducive to the heat dissipation of high-power devices.In this thesis,a wideband balanced and internally matched power amplifier operating at 2-6GHz is designed for the third generation GaN high electron mobility transistors.Compared with the advantages and disadvantages of the traditional wideband structure,this thesis adopts the wideband balance structure and wideband matching technology to design the power amplifier.The wideband balancing structure is realized by a third-order Wilkinson power divider/synthesizer.The Wilkinson equilibrium structure has the characteristics of broadband and insertion loss,and its isolation performance is excellent.The single-channel broadband matching technology is implemented by combining low-Q L-C pre-matching structure with multi-stage quarter-impedance transformation network.Due to the large difference between the impedance values of the input and output ports,this thesis adopts the combination of T-type pre-matching structure and multi-stage impedance transformation network for the output end,and the combination of two-stage L-C pre-matching structure and multi-stage impedance transformation network for the input end.The circuit is miniaturized by using aluminum oxide substrate to make inductance and impedance conversion network,and the Wilkinson power distributor/synthesizer was made on aluminum nitride substrate to ensure the reliability of the performance,For capacitor processing,ceramic medium with higher dielectric constant is used to realize the circuit miniaturization.In this thesis,GaN high electron mobility transistor developed by Qorvo Company is used to design a miniaturized wideband balanced power amplifier.The final power amplifier is encapsulated in a 63.68mm×28.85 mm shell.In order to achieve good heat dissipation shell,copper is used for processing and gold-plated treatment.The power amplifier works at the gate voltage of-2.8V and the drain voltage of 28 V.Under the power input of 34 d Bm,the average output power in the measured band is 36 W,the power additional efficiency is more than 35%,and the gain at small signal is more than 14 d B.