Research On The Application Of CRLH Circuit In Class-F Power Amplifier

Power amplifier(PA) is one of the important parts in RF and microwave systems. With the development of PA applications, the system puts forward higher requirements on the volume and efficiency of PA.Based on the background, this thesis will study the application that CRLH-TL(Composite Right/Left-Handed Transmission Line) was introduced to the design of class-F PA. Using dull-band CRLH-TL combine with class-F power amplifier can simplify the topology of PA circuit and reduce the size of match network, at the same time maintaining high efficency. Simultaneously, a dull-band class-F PA using CRLH-TL is presented in this thesis. Comparing to conventional dual-band PA, the dual-band class-F PA has the characteristic of simple structure, small volume and low costing.The specifically contents of this paper are listed as follows:The first part focused on the principle of F-class amplifier and CRLH-TL. Synthesis procedure, simulation and measurement of the dull-band quarter-wave(?/4) CRLH-TL open-circuit stub working at 5.2GHz and 7.8GHz are presented.The second part designed two kind class-F PA for the LTE band.(1) Study the mechanism of harmonic control network for class F PA. In order to simplify the topology of harmonic control network, the dull-band ?/4 CRLH-TL open-circuit stub was applied in harmonic control network for class F PA. So, a miniaturized and highly efficient class-F PA are obtained. The measured results show that the power-added efficiency(PAE) of this PA reached 70.6% with output power of 40.6dBm.(2) In order to improve the efficiency of class-F PA further and validate the input harmonic control network have a active effect to improve the class F amplifier PAE, a CRLH-TL input harmonic control network was added firstly on the PA based on the previous version. The test results show that the PAE of modified PA was higher of 2.7% than the original version.The third part proposed using CRLH-TL to design a dual-band high efficiency class-F PA. This class-F PA working at WCDMA bands. At first, this chapter introduces the design method of bias circuit including second harmonic control. By using this bias circuit combined with independence transformation network, the harmonic control network can be realized. And then dual-mode operation matching network is achieved by using the dull-band CRLH TLs. The optimization results show that output power of 41.127 dBm and 41.716 dBm was obtained at 1.7GHz and 2.14 GHz when input power was 29 dBm, respectively. In terms of maximum power-added efficiency, we obtained 71.67% and 62.92% at 1.7GHz and 2.14 GHz, respectively.