A Micro-power Ranging Impulse Radar Transceiver Subsystem

In recent years, the ultra-wide band (UWB) technology possessing some unique advantages has been taken more attention. As one of the UWB technologies, impulse radio is sending narrow width impulse signal at time-domain, producing a wide band frequency spectrum at frequency-domain and extreme low density of power spectrum. Because of its good characteristics, such as signal concealment, anti-covering, strong penetration, few power consuming, high distance resolution ratio, it has been extensively applied in military and civil fields. Impulse radar is using such technology to counteract the function which normal radar can not achieve, so it has attracted serious attention in military circle especially. The micro-power impulse radar described in this paper is designed for some kind of proximity fuse in military, realizing distance detecting.This dissertation mainly focuses on receiving and sending subsystem of micro-power distance detecting impulse radar. Through the theoretical analysis, stimulation, computer assistant design and experimental testing methods, a deep research work on this system is conducted.At beginning of the paper, the basic concepts of impulse radar and its progress and development in our country as well as abroad, in addition to what the background and meaning of the paper is, are introduced respectively. Based on the principle of normal radar, the entire scheme of distance detecting impulse radar is designed. Around the plan, the theories of narrow impulse generator, circuit system of digital signal processing and signal detecting are analyzed, then step recovery diode with the micro strip short-circuit line for generating narrow impulse, CPLD IC chip for finishing digital signal coding and decoding, ultra-high-speed comparator in latch mode for detecting signals are chosen.Secondly, the RF EDA software ADS is used to simulate the circuit of impulse source generator and optimize parameters. Altera QuartusⅡsoftware is adopted to program CPLD chip, realizing digital signal processing such as coding, decoding, timing simulation between each function block. At last, each part of the system fabricated on the experimental board is tested. The result of impulse source generator is in accordance with simulation. CPLD chip can produce coding signal. In the condition of timing adjusted properly and threshold voltage set well, narrow width impulse signal can be detected by ultra-high-speed comparator in latch mode.