Reseach On Desing And Implemention Of Transmitter Based On Rapid Pulse Shaping

The new navigation transceiver is one of the key components in the new navigation system.In this paper,the design and implementation of the transmitter of the ground transceiver in the new navigation system are taken as the main body;emphatically introduce the simulation,design and implementation of the high-power solid-state amplifier.According to the requirements of the system technical index,the pulse shaping filter technology is used to realize the spectrum forming,so as to meet the requirements of the new navigation system transmitter spectrum template index.Firstly,this paper taking the contents of the transmitter part of the Ground send& receive GBT broadcasting service system manual of the UAT data link technology of the United States Federal Aviation Administration(FAA),analysis and combined with the requirements of the project,put forward the technical specifications and implementation functions of the transmitter involved in this subject so as to meet the needs of the system.In order to improve the efficiency and spectrum characteristics of the transmitter,the design of the pulse forming part referenced the Digital Pre-Distortion technology,complete the overall design of the rapid pulse shaping transmitter on the basis of analysis of the non-linear characteristics of the power amplifier.The paper carried out the simulation design and implementation,centre on the main power amplifier,local oscillator unit,modulation and demodulation,pulse forming(including hardware and software).Through the unit circuit project design,device selection and key components simulation(including ADS simulation of the last stage power transistor,simulation of phase-locked loop)and so on,the related design work is already completed.On the basis of the realization of each unit circuit,through the joint debugging and testing of the hardware and software of the power amplifier and pulse shaping,the pulse shaping transmitter is realized.The transmitter completes the CPFSK continuous phase frequency shift keying modulation,the working frequency is 978 MHz,and the spectrum characteristics of symmetrical on both sides and monotonous decline,inhibition of more than 60 dBc in the deviation from the 3.25 MHz spectrum,and ultimately achieve output power output for 75 W emission.