Abstract: This design is a RF PLL frequency synthesizers. Can used frequency synthesizers can be used to implement local oscillators in the up-conversion and down-conversion sections of wireless receivers and transmitters. It is analogue device corporate ADF4116 series chip to adoptive. Summariness introduce know clearly on-chip low noise digital PFD(phase frequency detector), programmable reference(base)Frequency divider, multiplexer, programmable A and B counter, the dual-modulus prescaler, both 5 bit A and 13 bit B counters, etc. This chip have a high integrated level, performance best, cost low. Both incorporation exterior VCO and loop filter could rattling realize celerity Phase Lock function. Could versus signal passing programme came realize frequency demultiplication, could realize precise frequency synthesis output. It is transit simple three strung mouth control to chip possession internal storage.It is 2.7v to 5.5v to the device Working Voltage could, at the readiness ,low power dissipation use.