Design And Application Of Microwave Equipment Working At UHF Band

With the rapid development of electronic information technology, the amount of data generated in the communication is growing exponentially in modern society. China has made many of the world advanced achievements in electronic information technology both in the basic and system levels. At home, optical fiber communication is usually adopted in urban cities, but in some complex-terrain areas; remote mountains or emergency situations such as natural disasters.when the use of wireless communication become absolutely necessary. Digital microwave communication, as a wireless transmission method, has the obvious advantages in flexibility, resilience and mobility, comparing with optical fiber communication.The microwave equipment working at UHF band in this thesis is the most important part in communication system, which is mainly composed of digital processing unit, transceiver unit, duplex unit, amplifier unit, monitor and power supply unit. It mainly completes the wireless line-of-sight data transmission including the bulk services, engineering service and network management data. It can fulfill the communication between point to point and point to 2-7 points. And it's structurally compatible with point to multiple-point microwave communication equipment. The frequency changing can be realized by electrically tunable filter, which is with good anti-jamming feature. The use of LPI, FEC, total operating band frequency variable, DSSS and other measures is to achieve the anti-fading and anti-interception function. Interleaving, error correction and other measures is adopted to achieve channel error correction capability. The equipment can provide one engineering ordering channel and two relay engineering service channels, which guarantees the communication can be fulfilled in the opening and maintenance period not relying on the traffic channel for communication. The equipment also provides a remote-control channel, through which the remote equipment parameters such as bit error rate, the reception level, the transmission power and fault alarms and other parameters can be obtained between the two equipment wirelessly connected. The remote parameters can be queried so that the low probability of interception capability can become easier. The equipment monitor also supports parameter setting, parameter preview, fault alarm, fault finding, baseband loopback, IF loopback, RF loopback and audible alarm notification, etc. which is with good BITE function.According to the design specifications, with reference to various domestic and abroad microwave communication system design material, combined with my own condition, the thesis firstly describes the overall technical data and based on this the equipment design is done from the ECCM, transceiver isolation, receiving threshold, the system margin and other aspects. Then each functional module is respectively described from its function, technical specifications, composition, operating principal and application method and finally the structural feature, especially for the important digital processing unit and transceiver unit, which is explained in detail. Finally the test methods and data is given and the result shows that it meets the system requirements.