.30 Mhz, ~ 530mhz Broadband Power Amplifier Design And Research And Development,

At modern times, the power amplifier has a decisive role in the wireless communication systems; its performance will directly affect the performance of the whole wireless communication systems. The Radio of the military airplane put forward higher requirements for bandwith and output power of the power amplifier, when the software radio technology was proposed. In this paper, some key technical indicators of the power amplifier were analyzed in depth firstly, and then design methods of the broadband power amplifier were introduced. The design solution, the realization of technical indicators about this project were demonstrated in detail and the problems in the process of tuning and testing should be paid attention were mentioned at last.The objective of this project is to develop a power amplifier for 30MHz~530MHz, the output power of which is greater than 100W. The power amplifier has 500MHz bandwidth which acrosses five octave bands, so broadband matching technology is the key difficulty of this design, and there will be difficut to get so large output power in such wide-band. Therefore, the push-pull RF power transistors were used. The power amplifier was based on several technologies, including transmission-line transformers and microstrip mixed matching, magnetic ring on the transmission line for frequency band broadening, negative feedback circuits, frequency compensation and ALC and so on. The power amplifier was simulated using ADS and was tuned repeatedly, then a desired result was obtained.This design is based on the recent technology in and aboard, and engineering practice is based on the design theory of the broadband high-power amplifier. Some key technical indicators, the overall design and all parts of the circuit design which includes voltage-controlled attenuation circuit, excitation signal amplifier circuit, three power amplifier circuits and inter-stage matching circuits, were analyzed and demonstrated. The design solution, realization and notes were introduced particularly, and the results of testing were given at the end.