Shortwave Frequency Hopping Radio Automatically Fast Antenna Tuning System Developed

Self-adaptive Frequecy-hopping technique is newly developed in the shortwave communication system and has made a great renovation to the system.So the resarch of corresponding techniques become more and more popular.This subject derives from the project in that Chengdu Sine Science and Technology Ltd cooperates with the Southwest China Institute of Electronic Technology:"The development of front end of vechical-shipped shortwave communication radio".The author is in charge of the R&D of the broadband antenna system—automatic antenna tuning coupler . Through the compositive designation of hardware and software,we get the excellent broadband impedance characteristic from a small-sized whip monopole antenna that is only 2.4m high by means of instantaneous narrow band impedance-maching while satisfying the need of fast and frequency hopping in the band of 2~30MHz and gaining adaptability to the terrain. This suject in the whole shows innovations in the design and realization of circuit,software and system scheme.This paper make a deep analysis and argumentation of the broadband antenna system and discribe the merits and the limitations of them.Under the condition of the given monopole in the heighth of 2.4 the possibility of broadband impedance matching is discessed ,either. The system scheme adopted in the realization and the questions that should be paid attention to in the design and implementation of each functional unit in circuit are discussed in detail. The testing results of this subject are represented .At last the improvement to the subject is brought forward as a supplement.