Research And Design Of The Key Circuits Of Multi-Channel Super-Regenerative Receiver

Short range wireless communication systems have been widely developed and applied in resent years,so have the wearable devices.The super-regenerative receiver is characterized by its low power consumption,low complexity and low cost,and is extensively used in wearable devices.The traditional constructure of the super-regenerative receiver can only achieve the function of the reception of signal with a single frequency,which can not meet the increasing application demand of the wearable devices.Therefore,it is necessary to design a multi-channel super-regenerative receiver,which can implement the requirement of frequency selecetion.In this paper,based on a 0.18-?m CMOS process,the key circuits of a multi-channel super-regenerative receiver is designed.Programmable integer frequency divider in charge pump phase-locked loop(CPPLL)synthesizer is implemented first,with the employment of pulse-swallow structure.The divider consists of a 10/11 prescaler,a 5-bits pulse-counter and a 4-bits swallow-counter.By setting variable initial values to the counters,the programmable divider can realize different frequency devision ratios.A square wave quench signal generating circuit based on triangular wave generator is implemented,the output of which is periodic and not affected by the variation of the power supply voltage,so that it can periodically control the state of the super-regenerative oscillator.With these circuit modules realized,the stability of CPPLL is analyzed and simulated.Under the condition of CPPLL's stability and its short time of locking,the system of multi-channel super-regenerative receiver is simulated and its layout is designed.With the voltage supply of 1.8 V,the highest input frequency of the programmable pulse-swallow frequency divider is up to 1.5 GHz,the quench signal generating circuit can realize the function of generating periodic square wave signal which is irrelevant to the power supply voltage,and the multi-channel super-regeneration system can receive signals of 9 channels with the requency range of 315 MHz to 327 MHz and the frequency step of 1.5 MHz.This multi-channel super-regenerative receiver meets both function and indexes requirements,as a result,expands the application scope of wearable devices.