Experimental results for low-jitter wide-band dual cascaded phase locked loop system

Jitter is a matter of great concern for high-speed digital designers because of its ability to degrade the overall; system performance. Designing a low-jitter and wide-band phase locked loop (PLL) system is of practical importance because of its application in high speed digital systems. This paper presents experimental results of a low-jitter wideband dual cascaded PLL system using a single crystal oscillator. The first PLL employs a voltage controlled crystal oscillator (VCXO) to eliminate the input jitter whereas the second PLL provides wide bandwidth. Field Programmable Gate Array (FPGA) is used to generate a jittered clock source which is then passed through the proposed system to achieve wideband and low-jitter signal. Experimental results are presented to validate the proposed technique for different carrier frequencies.