Testing of Frequency Synthesizers for ZigBee Transceivers

Abstract

ZigBee is a wireless standard defined for low data rate applications with ultra-low power requirements. Devices based on this standard are expected to be low cost with a large battery life or use energy harvesting techniques. As a part of a major project for developing a fully functional RF transceiver chip complying with the standard, frequency synthesizers have been designed based on integer-N phase lock loops which are expected to work as local oscillators for both the transmitter and the receiver. The standard required the PLLs to be programmable to 16 channels in the 2.4-2.5 GHz range. One of the PLLs used an LC VCO while the other used a ring VCO. This work was meant to test these PLLs to make sure that they met the specifications required of them as per the standard.