Design And Implementation Of Wireless UHF Radio

With the development of times, technology, and battlefield environment, UHF communication is more and more extensively applied in military communication system due to its advantages of anti- interference, communication distance, transmission security, etc. The design of transceiver is the physical foundation of communication, because it directly determines transmission quality, and therefore decisively influences the performance of the communication system. The main work of this paper is to do a systematic research on UHF radio, The author ’s major contributions are outlined as follows:1. A set of IF sampling receiver is designed according to the requirement of bandwidth, receiver sensitivity, cost, modulation and demodulation schemes, and signal processing flow of the system. Gain in radio frequency, intermediate frequency and baseband frequency is properly allocated, and the scheme of automatic gain control is adopted, which greatly increases the dynamic range of the system. A front-end amplifier with low noise is designed, and channel is optimized, which reduces the noise coefficient of the system effectively, and also improves sensitivity and linear range.2. A direct up conversion transmitter with dual-channel and quadrature modulation is designed and implemented. By properly designed output impedance matching of the front-end power amplifier, the output signal power finally reaches 28 d Bm.3. RF matching circuit is studied. A method of circuit impedance matching by measurement and estimation with ADS simulation tool is proposed. device parameters and test environment are investigated, and input/output impedance of the device in working frequency are acquired, and finally matching network is computationally designed with ADS simulation tool. Effect is proved by verifying experiment.4. An electrically tunable bandpass filter with variable-capacitance diodes and high-Q inductors is designed. Performance is presented and proved by ADS simulation. In-band insertion loss is less than 2d B, and out-band attenuation is more than 40 d B.5. A digital signal processing platform is designed based on EP3C55F484C8. The platform is responsible for digital modulation/demodulation and systematic control, and it owns JTAG simulation interface and 128 general IO pins, which is the demand in future experiments.Finally, a complete UHF radio experimental platform is formed, and relative testing work shows that the platform meets the designing requirements.