The AFE7769D (4T4R2F) is a family of high-performance, multichannel transceivers, integrating four direct up-conversion transmitter chains, four direct down-conversion receiver chains, two wide-band RF-sampling digitizing auxiliary chains (feedback paths), and a low-power CFR/DPD for PA linearization. The AFE7769D has the following features to enable a low-power and small size multi-band radio design.

• The AFE7769D integrates four fractional RF PLLs to synthesizes the Local Ocillator (LO) signals for the transmitter or receiver to up-converter or down-converter mixers. In addition, each transmitter and receiver chain has an optional low-IF mixer, which can be used along with the LOs for frequency up-conversion or down-conversion.
• The direct RF sampling-based feedback path in AFE7769D offers an inherently wideband receiver chain to observed the PA output signal for DPD estimation, and also simplifies the calibration of TX chain impairments. Each feedback path has two switchable NCOs, which can be used to switch between two different RF frequencies when the two transmitter paths are operating at different RF frequencies, as in the example of this document. The NCO phase can be maintained during the switching.
• The integrated DPD engine in AFE7769D can linearize PAs with various output power level up to 50dBm+ (average power) and PA technologies (GaAs, LDMOS, GaN) with fast converging and tracking, and low power consumption. With DPD, power amplifies can operate with higher power efficiency while still meeting the transmitter RF emission requirements.