| Harmonic manipulation is an effective solution to efficiency enhancement for RF power amplifiers. In this dissertation, the theory and methodology of high-efficiency power amplifiers design using harmonic manipulation are studied thoroughly. The main contribution about this dissertation is summarized as follows:Firstly, the development of Class F power amplifies’output circuit is analyzed. Based on characteristics of the transistor device, a novel compact output topology is proposed. And the access to the initial design value of every element in this topology is introduced in detail. For the purpose of validation, a Class F power amplifier working at3GHz is designed and fabricated. When the gate bias is-2.8V, the drain supply is27V and the drive power is25dBm, this power amplifier delivers37.3dBm output power and72.3%power-added efficiency.Secondly, the necessity of input harmonic manipulation for realizing ideal inverse Class F power amplifier is demonstrated. The relation between input second harmonic and the drain current of inverse Class F is deeply explored. And the basic principle for input second harmonic manipulation is deduced. The simulation and measurement show that about6%improvement is achieved by adding input harmonic manipulation for a3.5GHz inverse Class F power amplifier’s efficiency. The optimum output power and power-added efficiency of this power amplifier is respectively39.4dBm and80%.Thirdly, a design approach of broadband high-efficiency power amplifier design is proposed. In this approach, some modifications are made given the effects of output second harmonic. Plus, more accurate transmission-line is applied for replacing the discrete component when implementing the wideband matching network. Through simulation, the design of a2-4GHz broadband amplifier is fulfilled. The efficiency of this amplifier keeps higher than50%across the entire band concerned. Thus, this approach’s availability is well verified. |
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