Research On An Ultra-wideband Pulse-signal Transmitter

Ultra-wideband technology is a relatively cutting-edge technology,it has a wide range of applications,Ultra-wideband system transmits a time-domain narrow pulse signal,and transmit information through the pulse signal,so the system can achieve the radar detection and short-range communication function,the use of pulse signals makes the detection radar has a high resolution,Ultra-wideband pulse signal transmitter is an important part of ultra-wideband system,Ultra-wideband pulse signal generation and transmission technology is a key technology in UWB technology research.Picosecond pulse signal generation technology is a prerequisite for the research of ultra-wideband technology,the bandwidth of the pulse signal is very wide,so the device involved in the system are working in a wide frequency band,and the design of the device is more difficult.Transmitting antenna must have a good time-domain performance,except for operating frequency bandwidth,Ultra-wideband antenna design is also a difficult point.The scheme of UWB pulsed emission system was proposed.In addition to considering the system performance,the low cost of the detection system,miniaturization is also taken into account.The main work of this paper includes the following parts.This article will focus on the above issues.In the first chapter the research significance and development of UWB pulse signal transmitter was introduced,in the second chapter,the selection of key parameters of UWB pulse signal transmitter and the key technology is introduced,the paper also briefly introduced the working principle of the detection radar,Ultra wideband signal selection was introduced,UWB signal generation method was introduced,and also Calculated the minimum transmission power required by the system.The third chapter introduced the design of the pulse source,which is based on the step recovery diode,the simulation model of step recovery diode was established,the parallel and series impulse sources are designed,single cycle pulse signal is desigened when impulse signal get through the adjustable delay line,and achieved a pulse width adjustable,parallel single-cycle pulse source operating bandwidth up to 5.3GHz,series single-cycle pulse source bandwidth up to 4.3GHz.The fourth chapter introduced the design of the transmitting antenna,and designed a TEM horn antenna and an Vivaldi antenna.The working bandwidth of the Vivaldi antenna reached 5GHz and the gain is up to 7.9dB.Chapter 5 introduced the design of amplifier circuit,the designed power amplifier has a gain of 14 dB at the center frequency of 3GHz.Chapter 6 introduced the test of the hardware,and analyzed the test results,the designed Ultra-Wideband pulse signal transmitter was tested.The Final chapter is the sum up and outlook,in this chapter the shortcomings of the system was analyzed,and put forward the system improve scheme.The proposed and designed Ultra-Wideband pulsed emission system in this paper can achieve the expected function,can be applied to liquid surface detection,and meet the design requirements of the system.