Research On Key Technologies Of Ku Band Transceiver Front End

The Ku-band transceiver front-end is an important core component of satellite communication.It implements down-converting the weak RF signal received by the satellite antenna into an intermediate frequency signal and a beacon signal,and simultaneously up-converts the intermediate frequency signal to the RF signal to drive the power amplifier to transmit it through the satellite antenna.The system satisfies the requirements of the satellite communication system,so the research on the Ku-band transceiver front-end is of great significance.Based on the application background of the project,this paper introduces the current situation of Ku-band transceiver front-end used in satellite communication at home and abroad in recent years.The module integration method adopted by this project is also a front-end design method widely used in recent years.This dissertation introduces the design process of a Ku-band based transceiver front-end.Firstly,the structural characteristics and applicable scenarios of different transceivers are analysed.The proper transceiver structure is selected.The important phase-locked loops and filters of the transceiver front-end are introduced in detail.Then,according to the requirements of the system,the Specific implementation methods are put forward.The implementation method is divided into a local oscillator phase-locked loop,a Ku-band receiving module and a Ku-band transmitting module.The Signal synthesizer used as a fixed low frequency local oscillator and a variable high frequency local oscillator to achieve twice frequency conversions.The receiving module realizes downconversion of the weak signal of 12.25 GHz to 12.75 GHz to the first intermediate frequency 1 GHz signal,and then use a splitter to put the power into two part.One channel acts as a beacon signal for searching the star,and the other channel continues to downconvert to 70 MHz as the intermediate frequency signal for outputing.The transmitting module realizes that the 70 MHz intermediate frequency signal is first upconverted to 2.75 GHz,and then upconverted to 14GHz~14.5 GHz,the driver's amplifier is used to drive after 40 W power amplifier.This dissertation details the project's production and testing of various indicators of the system.The test results show that the noise figure of the receiving front-end is less than 1dB,the total average gain is 83 dB,the spur suppression is better than 55 dBc,the transmitting module total gain is greater than 45 dB,the output power is up to 28 dBm,and the 40 W power amplifier can be driven.The project has rich engineering value in the field of satellite communications.