Research And Design Of S-band T/R Module

With the development of the communication and radar technology,transmit/receivemodules is widely applied in the military and civilian areas of the communication,thenavigation.The thesis is focused on the S-band transceiver.The main modules are analyzedin theory, designed and manufactured according to the engineering application.Through the integrated scheme comparison and the existing experiment condition,thedesigning scheme of the S-band transceiver is proposed according to the system designindex.The superheterodyne structure is used in the module.The transmitter and receiverboth use the double-convertion structure,and the module is divided into several componentssuch as RF circuits,IF circuits,frequency synthesizer,FPGA control circuits and powersupply[1]7.The system works in FDD(Frequency Division Duplex) mode.The transmitterpart is include of the up-conversion,filter,power amplifier,and the receiver contains theLNA(Low Noise Amplifier),filter and the down-conversion.The T/R module can stop theinterference of the out-band signal and suppress the leakage of the local oscillation.Fourvibration signals for mixing are produced by frequency synthesizer and provided to thetransmitter and receiver.And,the FPGA control circuits input control words to the PLL(Phase-Locked Loop) chip to complete the function of the frequency selection.It is difficult for the T/R module that is the channel between antenna and signalprocessing to launches and accepts the S-band signal and to achieve certain power andsensitivity,has characters of low-noise,low-spurious and high image-frequency rejection atthe same time.The topic researches the structure and design of S-band T/R module. Lastly,aS-band T/R module is developed and the analysis of the result is also introduced.Thereceive gain is higher than50dB;the transmit gain is higher than30dB,the transmitterpower is higher than-115dBm.The phase noise level is less than-80dBc/Hz@10kHz.Thespurious suppression of the module is greater than50dB,because there is a dielectric filterfor S-band signal after the mixer. The local oscillator leakage and output power of imagefrequency is less than-60dBm.System works stability and has good performance.