Research And Application On High Performance Frequency Synthesis Technology

With the rapid development of modern electronic technology, the demand of research on frequency synthesizers with excellent performance simutaneously, such as frequency stability, frequency purity, hopping speed, frequency coverage, etc, has been urgently raised. The properties of microwave and millimeter-wave signals such as short wave length and wide bandwidth are useful for the military guidance and electronic countermeasures, and therefore have attracted increasing concentrations.In this dissertation, the basic theory of frequency synthesis is discussed. Then the novel and improved algorithms and structures of frequency synthesis are proposed:1. A novel frequency synthesis algorithm to achieve wide frequency coverage and low phase noise is proposed. By adjusting the gain of phase frequency detector (PFD) of phase locked loop (PLL) to compensate the nonlinear behavior of voltage controlled oscillator (VCO) and keep the loop bandwidth of PLL approximately constant, both of agilty and frequency purity of synthesizer over the output bandwidth can be ensured.2. An improved multiple-tuned PLL driven by DDFS (Direct Digital Frequency Synthesizer) structure of frequency synthesizer is proposed. By tuning multiple factors in the frequency syntheizer structure, the flexibility of frequency configuration can be provided to achieve high performance.3. A design approach of microwave and millimeter-wave transceiver is proposed. By optimizing the frequency configuration of up-conversion and down-conversion structures, the advantages of DDFS, PLL and FPGA (Field Programmable Gate Array) can be fully taken to achieve high performance on frequency purity and swithing time simutaneously.4. A novel truncation spurious free DDFS structure and algorithm is proposed. By introducing a comparator and an adder into the traditional DDFS architecture, the phase truncation spurs of DDFS can be eliminated without increasing hardware overhead significantly.