Microwave PLL synthesizer eliminates frequency-doubling in broadband, point-to-point and multipoint wireless apps

NORWOOD, USA: Analog Devices Inc. has introduced a PLL (phase-locked loop) frequency synthesizer that can be used to implement local oscillators as high as 18 GHz in the up-conversion and down-conversion sections of wireless receivers and transmitters.

The exceptionally high bandwidth of the ADF41020 allows designers to potentially eliminate a frequency-doubler stage, which simplifies system architecture and reduces cost in applications including microwave point-to-point and multi-point radios, wireless infrastructure equipment, VSAT (very small aperture terminal) radios, semiconductor test equipment, radar applications and private mobile radios. With an operating bandwidth up to 18GHz, this represents the highest frequency PLL available on the market today.

“The ADF41020 PLL is the latest addition to ADI’s leading portfolio of phase locked loop synthesizers and extends our portfolio into higher frequency ranges,” said Peter Real, vice president, Linear and RF products, Analog Devices. “This new PLL helps significantly reduces component count and system cost while continuously improving performance in next-generation radio designs.”

The ADF41020 PLL frequency synthesizer consists of a low noise, digital phase frequency detector, a precision charge pump, a programmable reference divider and high-frequency programmable feedback dividers. A complete synthesizer can be implemented if the PLL is used with an external loop filter and VCO (voltage controlled oscillator). The PLL can be used to drive external microwave VCOs via an active loop filter. The pin-out matches very closely the pinout of the ADF4106/7/8 family of integer-N PLLs, meaning only a minor layout change is required when updating a design to take advantage of the much wider bandwidth.