| Ultra-wideband (UWB) radar is a new system of radar, with its wide signal bandwidth and the high range resolution (HRR), the UWB radar is widely applied in radar detection, imaging, precise position, target identification technologies and so on. The UWB radar technology is mainly used in the military field at the earliest, the ultra-wideband technology has aroused more and more attention since the Federal Communication Committee (FCC) released the standards of the UWB in 2002.The impulse radar is a typical application of the ultra-wideband technology, it get the distance information by basing on the time interval between the transmitted pulse and the echo. The impulse radar launches the extremely narrow pulse width of ultrashort pulse, whose magnitude usually is ns or ps. This paper mainly studies the technology of the radar signal generation and emission, as well as the emission signal encoding. Main research contents are as follows.(1) Research the wave shape of the impulse radar system.(2) Discuss and research on many sorts of narrow Pulse generators technology. Namely, the Pulse generator circuits based on Tube Diode, avalanche transistor, Step Recovery Diode (SRD), photoconductive semiconductor switches (PCSS), and compared a variety of circuits. Based on the simulation, two narrow-pulse generator circuits have been designed. In the actual test, relatively good waveform has also been obtained.(3) Encode the emission signal to increase its anti-interference performance.(4) Through the circuit simulation and actual test, the constructing and debugging of the radar transmitter hardware circuit have been completed. After the test of high-speed broadband oscilloscope, more ideal waveform and amplitude, as well as narrow-ns pulse width level have been obtained. Guided by the theory of signal integrity, the PCB design has been finished, which can provide a certain degree of support and reference function for small impulse radar transmitter system design, and high-speed PCB circuit design. |
PDF Full Text Request