The Design And Implementation Of 2.4GHz PLL Frequency Synthesizer

Now with the rapid development of electronic science and technology, the demandfor electronic products of people is more and more bigger, in the heart of electronicsystem "frequency synthesizer" is to get people to focus on. Frequency synthesizer iswidely applied in various fields, such as aerospace, missile guidance, communication,etc. Traditional LC oscillator and crystal oscillator has its own shortcomings, can’tsatisfy people’s needs. Therefore, the study of frequency synthesizer technology hasimportant practical significance.In this paper, we designed a2.4GHz phase-locked frequency synthesizer. First, weanalyzed the current development situation of frequency synthesis technology,choosedthe charge pump phase-locked frequency synthesis technology. followed by a verydetailed elaborated each part of the charge pump phase-locked frequency synthesizercircuit composition, working principle, mathematical model and the linear dynamicequation. and also puts forward a number of steps to lower phase noise and spurious inthe actual design of frequency synthesizer.Finally, put forward the scheme of integerphase lock loop technology with three order loop filter frequency to implemet.In the design we first selected the PLL chip ADF4108and VCO MAX2750chip tobuild system, introduced two chips selection and specific chip configuration, thenanalyzed the loop filter design, and further introduced the design method of loop filter,we choosed the better performance of third order loop filter, and through the program tocalculate the component values, through matlab simulation to test that loop filter designwas correct, then we demonstrated the whole system by ADIsimPLL software system,tested system design, including the noise index of the simulation, Finally we completedthe system design principle diagram and PCB version, and tested the frequencysynthesizer, analyzed the results.test results and the expected design goal werebasically identical.