Broadband Fine Stepper Low Spurious Signal Source

In this paper, it introduces the design and experiment of the RF part of a 10MHz～3.2 GHz wide bandwidth, low resolution, low spurious frequency synthesis equipment. In the RF part of the frequency synthesis equipment, it contains different kinds of circuit modulars composed of frequency multipliers, frequency dividers, filters, DDS(Direct Digital Frequency Synthesis), PLL(Phase Locked Loop), ALC(Amplitude Loop Control) and sampling mixers etc. The main work of the author is the general design of the 10MHz～3.2 GHz frequency synthesis equipment, and also includes the design of 11MHz low phase and low spurious frequency source, 19MHz～39MHz DDS frequency synthesis, 400MHz low phase and low spurious frequency source, 1GHz～9GHz wideband sampling mixer, 2.4GHz～3.6GHz wideband bandpass filter and the final debug work of the system.The architecture of DDS+PLL+sampling mixer is adopted in this paper to obtain the wide bandwidth, low resolution,low spurious basic source of 0.8GHz～1.6GHz. This basic source has both the merit of DDS such as low resolution, easy to realize the frequency modulation and phase modulation, and the narrow-band tracing filter merit of PLL to obtain the low spurious. Then it use this basic source to generate a 10MHz～3.2 GHz wideband,low resolution,low spurious frequency source by frequency multipliers, frequency dividers and filters etc. The whole system need elaborate consideration to avoid deteriorating the phase noise or spurious created by improper design.In this paper, it first introduces the general architecture of the 10MHz～3.2 GHz wide bandwidth,low resolution, low spurious frequency synthesis equipment. Then it presents the theory and design of PLL frequency synthesis, DDS frequency synthesis and filters. Then it elaborates on analysis of feasibility of this architecture, the realization of concerned modulars and some questions, which must be paid attention to in the system design. At last, the ultimate experiment result of this subject is representedand analyzed in detail.