Study On Broadband Power Amplifier At 100-400MHz

In modern communication systems for mobile, whether it is Code Division Multiple Access communication systems (CDMA), Global System for Mobile Communications (GSM), or Universal Mobile Telecommunications System (UMTS).Broadband power amplifier design usually require high performance, including wide operating bandwidth, high linearity and in-band gain flatness.The goal for this project is to design a broadband power amplifier with working frequency in the 100MHz-400MHz, output power of 10 watts, requiring that their band gain flatness work well, taking into account the efficiency and linearity, so the design is difficult.This paper first introduces the significance of broadband power amplifier research and development status. The second chapter describes the basic theoretical knowledge required in the design of broadband power amplifier, including a basic description of the power amplifier and the basic model. This chapter also specifically describes the design of broadband power amplifier using broadband matching theory. The third chapter describes the specific EDA simulation of broadband amplifier design process. A detailed discussion of the simulation result is showed, including static working point, stability, DC bias, input and output matching and small signal and large signal performance, etc. Chapter IV describes the broadband power amplifier assembling and debugging process, analyze the problems appeared in debugging to find out the cause and get a solution. At last the overall test of the amplifier gives the test results of the small signal gain flatness and large-signal single-tone test as well as two-tone signal linearity test.The results show that the small-signal gain flatness of the amplifier is about±0.06dB,when the output power raise to 10W,the in-band gain flatness is better than±1dB,when the efficiency is about 25%.Two-tone signal with a tone spacing of 1MHz,the IMD3 is about -19dBc.