Research And Design On Ku Band Transceiver RF Front-End

With the rapid development of science and technology, satellite communication system, radar systems and other wireless communication systems have been widely used in many important areas, such as military, commercial and scientific researches. Radio frequency(RF) front-end is an important part of wireless system. Its performance has a decisive effect on the stability, bandwidth and dynamic range of a wireless system. Therefore, there is great necessity on the study of RF transceiver front-end.Ku band and Sub-1GHz band are two important frequency bands in wireless communication. Comparing with that in C band, the receiving antenna in Ku band is with high efficiency, wide frequency band, and is subject to less microwave radiation interference from ground. Hence it is widely used in the satellite communication. Sub-1GHz band, such as 314-316 MHz, 433.00-434.79 MHz and 862-870 MHz, is used for short distance wireless transmission systems. It is applied in the field of sensors, instrumetation, and the Internet of Things. This thesis focuses on the realization of frequency conversion transmission between the two hot bands. A RF front-end system based on phase-locked loop technology and 4th harmonic mixer technology is designed. And finally the accuracy of the data transmission of the system is verified with LCD display terminal.The proposed Ku band RF front-end consists of a transmitter and a receiver. A modulated Sub-1GHz signal, with the carrier frequency of 315 MHz, is directly converted to 14.315 GHz ? 150 MHz, which belongs to Ku band, by 4th harmonic mixer in the transmitter. At the receiving end of similar structure, the Ku band signal is converted to Sub-1GHz signal. Then the signal is demodulated and the the received data displayed through the LCD. The received data is compared with the transmitted data, to confirm the system PER(packet error rate). Considering the time factor, SmartRF TrxEB evaluation kits produced by the Texas Instruments(TI) company were used as the modulation and demodulation circuits for Sub-1GHz signal. In the process of designing and implementing of the whole system, the main technical difficulties including the following 5 parts:1. Analysis of parameters of the transceiver and demonstration of transceiver system performance;2. Design and test of 4th harmonic mixer;3. Design of mirror frequency suppression filter;4. Design and test of Local Oscillator source based on phase-locked loop technology;5. Design the antenna and verify the data transmission accuracy of completed modules with SmartRF TrxEB evaluation kits.