Design Of The UWB Narrow Pulse Generator

Ultra-wideband communication technology has been widely used in various fields for its advantages of high data transmission rate,low power consumption,low cost,good security,and sharing of spectrum resources with traditional narrowband communication technologies.The scarcity of spectrum resources and the issue of high-speed data transmission in communication technologies provide new ideas.The most important part of UWB communication technology is the generation of suitable UWB pulses.Therefore,it is of practical significance to study how to design ultra-wideband pulse generators with good performance.This article first introduced the development history and research status of UWB technology.Then it introduces the principle of UWB technology,the characteristics and application fields of UWB technology,compared with the advantages and disadvantages of ultra-wideband technology and traditional communication technology.It also analyzes the time-domain and frequency-domain characteristics of UWB pulse waveforms in detail.It mainly studied that integrated circuit of avalanche transistor,avalanche transistor in parallel and step recovery diode ultra-wideband pulse generator,and Using ADS software to perform simulation analysis of the time domain and frequency domain.In view of the ultra-wideband pulse amplitude is low for the step recovery diode pulse generator and avalanche transistor pulse generates a low pulse repetition rate.The spectrum of pulse waveform produced by two methods does not meet the shortcomings of FCC spectrum regulation.It is carried out the circuit optimization.Because the step recovery diode generally produce ultra-wideband pulse using the principle of microstrip line reflection,the signal amplitude is too low and the frequency spectrum cannot meet the FCC requirements.This paper proposes a method that does not require microstrip lines to generate ultra-wideband pulses.The method was simulated by ADS software to obtain the class gaussian second-order derivative function pulse with a pulse amplitude of 4V,The pulse width is about 1ns,and the-10 dB bandwidth is about 2GHz-6GHz.Due to the low repetition frequency of the avalanche transistor pulse and the frequency spectrum that does not meet the FCC spectrum requirements,In this paper uses a combination of double avalanche transistor in parallel with capacitance and inductance to generate ultra-wideband pulses.After ADS software simulation,the pulse repetition frequency can reach 50 MHz.The ultra-wideband pulse has a Gaussian first-order derivative function pulse width of approximately 1.3ns,a Gaussian second-order derivative function pulse width of approximately 1.8ns,and a-10 dB bandwidth of approximately 2GHz to 5GHz.The results of simulation analysis are basically the same as expected.the ultra-wideband pulse circuit generated by the two methods is simple and easy to implement.It does not require spectrum shifting to satisfy the relevant frequency spectrum regulations.It has a good reference value for the practical application of ultra-wideband pulse generators.