Design Of RF Front-end For Portable Radiosonde Receiver

The development of meteorological observation technology involves many aspects of national defense and national economy. The weather forecast, aircraft, ship transportation, prevention and control of atmospheric pollution and so on are closely related with meteorological data. With the rapid development of science and technology and national economy, all kinds of environmental problems are increasingly serious. In such circumstances, the meteorological data is become more and more important. Diversity, precise meteorological data’s acquisition, we need the support of all kinds of high performance detection equipment. According to the actual development situation of meteorological equipment, to meet the needs of engineering, in this paper a RF front-end circuit design of portable weather sonde receiver is studied.Receiver is an important equipment of communication and transport. The function of the receiver is receiving meteorological data. It plays an important role of the portable detection system. Through the analysis of advanced foreign sounding system to determine the architecture of RF front-end circuit system, combined with the actual demand of detection, to determine the system performance of each part. The RF front-end circuits including low noise amplifier, filter, mixer, and automatic gain control circuit, etc. Every part of the circuit has been studied. To combine with the simulation software, the detailed design processes are given. The receiver adopts super-heterodyne topology structure. First, the signal which received by receiving antenna carries meteorological data information through the low noise amplifier amplification, after filtering the signal will be processed in the mixer, at last, an automatic gain control circuit is used for signal amplification. To meet the requirements of low noise and high gain amplification, LNA uses two stage amplifier structures. The mixer is a one stage down-conversion structure. The part of Automatic gain control ensures the stability of the gain of the whole system.After finishing the design of each part, the cascade simulation is carried out for the whole front-end circuit. Combined with the simulation results, the feasibility of the system circuit is verified. Finally, the hardware circuit of all parts of the design is completed. Test results and analysis paper are given after finishing the actual production and debugging.