1.1 Ghz Synthetic Signal Source Module Design

The Synthesized Signal Source is a RF signal source, which takes high stability oscillator as standard and uses frequency synthesis techniques to form the desired frequency. It has extremely high output frequency and accuracy, and its signal characteristic parameters are controllable. The controllable signal characteristics, mainly refers to frequency, amplitude (power), and modulation format parameters of the output signals, they can be artificially controlled setting.Because the characteristic parameters of the Synthesized Signal Source signal can be artificial set, so it can easily simulate different signals with different characteristics in all cases, it is particularly useful in production development and circuit experiment, In circuit test, measuring the contrast input and output signals, can be used to determine whether the functions and features of the signal processing circuit to meet the designed requirements.The design of1.1GHz Synthesized Signal Source Module one of the key modules of the multi-function tester. This thesis describes how to use Direct Digital Frequency Synthesis, Phase-Locked Loop and Mixer technology to produce a broadband frequency signal, and improve the preliminary design frequency synthesizer module. This theses includes:(1) Improve the pre-design, differentiate the function modules and reproduce the PCB and the cavity.(2) Design and implement the FM, AM and PM, in order to increase its modulation.(3) Designed the amplification and attenuation module, in order to meet its dynamic range and maximum output power.(4) Design segment filter module to suppress the harmonics of the signal to meet the harmonic index. Repeat to test the loop filter and find appropriate loop bandwidth in order to meet the index requirements to stray.(5) Achieve the control timing of programmable chip in FPGA. Only use MCU to achieve communications functions and use advanced FPGA, in order to resolve the problems of the capacity of MCU and resources of FPGA ports of input and output.This thesis formulates appropriate methods to test whether1.1GHz Synthesized Signal Source Module meet the designed requirements. The test results show that the1.1GHz Synthesized Signal Source Module has meet all the designed requirements.