A SIMPLE METHOD TO DESIGN PHASE-LOCKED LOS FOR CDMA MOBILE COMMUNICATIONS-SYSTEMS USING CAD TOOLS

A simple method to design phase-locked oscillators for code-division m ultiple access (CDMA) mobile communications systems based on the IS-95 standard is presented. A CAD tool is developed to design and optimize the passive third-order loop filters for current-mode charge pump fre quency synthesizers. As ct result, optimized loop filters with minimum phase noise, a wide synchronous bandwidth and high stability are obta ined. VCOs ave designed and optimized using SuperCompact(R) software t ools. Finally, four phase-locked loop (PLL) oscillators ave designed a nd employed in the system. Good performance is demonstrated in the det ailed experiments.