Study On K Band FDD Communication System Tranceiver Front-end Technology

Microwave has a rich spectrum resource. Taking the advantage of its widebandwidth, the broadband communication, which improves the capacity of informationtransmission, can be implemented in microwave wireless communication system. Thecompact K-band planar transceiver front-end, which is mainly used for microwavepoint-to-point communication, covering the frequency range of21.2~22.4GHz and22.4~23.6GHz using frequency division multiplexing (FDD) full-duplex mode isstudied in this thesis. At Temporary venues or in remote mountainous areas, optical fibercommunication can be replaced with it, which serves as microwave radio relay in highvolume data transmission. When compared with optical fiber communication, it has theadvantages of convenience, flexibility and low-cost in construction.The realization of signal chain circuit of compact K-band planar transceiver isstudied using the method of partial module circuits verified before overall circuit designin this thesis:1. The architectures of receiver and transmitter are determined after some commontypes are studied and two schemes of transceiver front-end are proposed.2. The downconverter and IF partial modules are designed and verified after thedetermination of transceiver’s scheme and receiver’s architecture. The specific circuitarchitecture is confirmed with the help of experimental results.3. The partial modules: baseband modulation, K-band amplifier chain and K-banddetector are designed and verified after the determination of transceiver’s scheme andtransmitter’s architecture. The problem of gain shortage in K-band amplifier chain isanalyzed and solved. The specific circuit architecture is confirmed based on theexperimental results.4. The overall transceiver is designed and implemented with planar hybridintegrated circuit technology. The dimension of it is230mm×100mm×8.5mm with9.9W DC power consumption. The problem of noise figure in receiver and gain intransmitter are analyzed and solved in the debugging process. The test results show theconsistency with design specifications. 5. Two pieces of advance, which don’t change the transceiver front-end’s hardwaredesign, are proposed to improve its performance which isn’t well enough during testingprocess.