| The terrible channel characteristics are unavoidable questions concerning the mobile television on vehicles. To keep stable transmission quality in such condition, it's necessary to take some measures to reduce the bad influence. When vehicles are running, the smart antenna may improve the multi-path influence due to the buildings'disturbance and weaken Doppler Effect due to quick changed environment. So it is hopeful to apply the smart antenna on mobile television. The research purpose of this paper is to improve the existent smart antenna project and make it suited for the mobile television system to receive volume-production. To reduce cost and receive a high standard, the phase shifter is mainly researched.First,the article analyzed the domestic and overseas actualities of smart antenna,mobile television and phase shifter. Compared several existent mobile television standards and pointed the key question to needed. Chose digital-analog smart antenna by comparing several smart antenna systems. Defined the phase shifter model and simulated the phase shifters capability of three reflective loads. Made use of existing components to design a smart antenna phase shifter which was used in mobile television. Then optimized it by two measures and simulated the better capability. At last, according formula analysis to explain the influence of phase shifter to smart antenna weighted network and validated the controlled capabilities.The research indicated that, it is feasibility to applies smart antenna on mobile television. Strength the smart antenna's usability by using digital and analog smart antenna structure. Used the improved phase shifter structure, it is hopeful to reduce the weight and volume of the smart antenna; Linear measure may less than 3.1% by choosing the better data and the insertion lossfluctuation less than 3dB. The designed phase shifter can satisfy adjust phase linearization and settle for the digital-analog smart antenna of mobile television need. |
PDF Full Text Request