Failure to lock: Why wideband PLL frequency synthesizers lose lock

Wideband frequency synthesizers have become more popular recently because they allow software-defined radios to address the diverse frequency bands in LTE, MC-GSM, WCDMA, CDMA, TD-SCDMA and WiMAX infrastructure systems with shared hardware.

Although several manufacturers offer built-in algorithms that automatically select from integrated multiple voltage-controlled oscillator (VCO) and capacitor array structures, many system designers still find themselves wondering, “Why won’t the phase-locked loop (PLL) lock properly?”

Applications engineer Pete Hanish takes a look at common user implementation errors and fixes in his in-depth article for RF Globalnet. Click here to read more on his practical identification and correction methods.