Research On Ka/K Inter-frequency,Ku Time Division Dual Band Satellite Transceiver Front-end

Satellite communications are playing an increasingly important role in modern times.As a key component,the transceiver plays a decisive role in the normal operation of the equipment,making people's requirements for their equipment higher and higher.C-band and Ku-band related technologies are now widely used due to their early development,but they face the problem of limited spectrum resources.Therefore,the development of high-frequency bands has become an inevitable trend.At present,most countries have developed towards the K and Ka bands,and a few countries have moved towards the research of the EHF band.Due to the different research time of related technologies at home and abroad,there is still a certain gap between domestic and foreign products.Therefore,it is of great significance to study a Ka/K hetero-frequency,Ku time-division dual-band satellite transceiver front end.The main application background of this topic is vehicle-mounted satellite communication,and the vehicle-mounted satellite emergency communication system is an emergency communication command system supplemented by satellite communication,combined with various wireless communication means including short-wave,ultra-short-wave and other short-range communications.Starting from the background and theory of project application,this thesis expounds its important engineering application value.This thesis introduces the design and implementation of a Ka/K inter-frequency,Ku time-division dual-band satellite transceiver front-end.In this design,a phase-locked local oscillator source is used to drive the Ku-band transceiver front-end,which is multiplexed as the Ka-band transmitter local oscillator,and another phase-locked source is used as the K-band receiver local oscillator.Modular design Ka/K inter-frequency transceiver front-end,Ku time-division transceiver front-end,microwave channel module and power supply and control circuit,each module is integrated in a shielded chassis through cable interconnection.The final test results show that the transmitting channel gain is higher than 62 d B,the gain flatness in the signal bandwidth is less than 3.38 d B,and the maximum output power is higher than 5W,of which the Ku transmit channel achieves spurious suppression better than 55 d Bc and harmonic suppression is better than 50 d Bc.The receive channel receives a gain greater than 50 d B,a receive noise figure of less than6.4d B,a gain flatness of less than 2.5d B,and a receive dynamic range greater than70 d B.It has the characteristics of wide signal bandwidth and good phase noise.