Design Of X-band Phase Lock Loop

Since the phase-locked loop (PLL) is the important part of wireless equipmentsand X-band PLLs are widely used, it is necessary to research on X-band PLLs. BecauseGaAs HBT is characterized by high speed, low phase noise, high operating frequency,strong radiation ability to radiation and so on, the design of an X-band PLL in1μmGaAs HBT process technology has been proposed in this thesis.Firstly the operation principles and performance parameters of a PLL has beenintroduced, the noise performance and designing of loop parameters also beeninvestigated. Then the design of each function block in this PLL is given in detail. TheVCO is designed by using the small-signal S parameters, and the phase noise of-117.4dBc/Hz@1MHz is achieved. A division ratio of135-263and high divisionprecision are achieved by a high-speed programmable frequency divider which is madeup with a new structure. In addition, the PFD which is virtually free of dead zone andthe charge pump with high current matching characteristic are designed.At last, the proposed circuit has been simulated. This simulation results offrequency resolution50MHz, lock time7μs, output frequency range9.80GHz-10.15GHz with8channel are achieved, the perforamce of this PLL has beenshown stable and high precision. According to the character of Mixed-Signal circuits,the layout of the PLL has also been completed in this paper.