Ku-band Broadband Low-noise Radar Frequency-hopping Source Development

Frequency Synthesizer is the heart of all the electronic systems. It determines the performance of the electronic equipments,plays the most important role in our lives. Along with the development of wireless communication, modern military and national defence, many systems such as radars, homing weapons, measure equipments need higher and higher performance of frequency synthesizer, wide frequency range, low phase noise, high spurious restraining, low jumping time and high working frequency. Most countries in the world have been playing more attention on the design of it.At first, briefly introduces the development and the application and research of the microwave frequency source in home and abroad, and the main contents of this thesis.Secondly, principal introduces the theory of PLL design. Include the component , principles and performance of PLL. Besides, several common used PLL structure and their merit and defect are presented. Then do a research of PLL frequency source on two key feature—phase noise and spurs.In this chapter, deduce the phase noise and spurs of caculating model and give the third loop fliter of design method to improve the perfermance of PLL frequency source. At last, give an example ,"Ku wide-band low noise radar hopping frequency synthesizer", to detail the practice of PLL frequency source. There are many difficulties in this project, such as high working frequencies, very low phase noise, wide band and hopping. Therefore , the hybrid frequency sythesis technology: PLL+Mixer is adopted. MATLAB and ADS are employed to help design. Moreover, we provide the testing result and photos of Ku wide-band low noise radar hopping frequency synthesizer.