The Design Of K-band Group Delay Calibration Transceiver System

Modern microwave and millimeter wave transceiver system occupies an essentialposition in civil communication systems, satellite navigation systems, integratedelectronic warfare systems, phased radar systems and precision-guided systems. Withthe development of theory and hardware/software techniques in these fields, people putforward higher requirements on transceiver system about its transmission capacity, coderate of data transmission, transmission performances in time/frequency-domain andconsistency. The fundamental purpose of these requirements is the signals transmissionwithout distortion. In order to ensure the phase-frequency characteristics of thetransceiver system and achieve signal transmission without distortion, it is veryimportant to measure and calibrate the group delay of the transceiver system quickly,time-actually and precisely.Base on the above issues, this paper aims at the group delay calibration of K-bandtransceiver system. On the foundation of thorough analysis of the design principles ofevery transceiver system modules, a group delay calibration transceiver system isdesigned. The main content includes:1. Design methods of receiver and transmitter in transceiver system are analyzed.Based on the design principles of group delay calibration transceiver system, thestructure schemes of the receiver and transmitter of the group delay calibrationtransceiver system are proposed. The receiver of this calibration transceiver system usesimage-rejection receiver method. Image-rejection mixer and directional coupler are usedto achieve both suppression of mirror-frequency interference signals and requirementfor low group delay. The local oscillator branches use multipliers to achieve frequencymultiplications of X-band signals provided by phase-locked loop module to ensure thepurity and stability of local oscillator signals.2. According to the principles and main parameters of the devices in every RFmodules, the main chips used in the RF modules of the calibration transceiver systemare appropriately selected. Specific performances arrangement of receiver channel andtransmitter channel are given. The out-put spectrum characteristics and the P-1value of out-put power of this circuit are simulated. Finally, lower/higher-conversions offrequency, which can meet the requirements, are achieved.3. According to the design principles of the phase-locked loop module and theoperational principles of its functional devices, performances arrangement of thephase-locked loop and selections of functional chips in this calibration transceiversystem are carried out. Then the phase-locked loop circuit is designed, which providestable and frequency-hopping local oscillator signals with low-phase-noise to this groupdelay calibration transceiver system.4. The cavity and power source of this calibration transceiver system are designed,respectively. And the fabrications of this system are completed. The performances of thereceiver/transmitter channels and the group delay characteristics of this system aremeasured. The measured results are analyzed.