Accurate phased-array antenna calibration is essential for maintaining consistent beamforming performance across transmit and receive channels. Channel-to-channel variations in gain and phase can degrade beamforming accuracy, reduce array gain, and increase sidelobe levels. These effects must be calibrated to maintain desired antenna performance.

Traditional calibration architectures can require dedicated RF switches for individual transmit and receive channels, increasing component count, board area, routing complexity and time, particularly in large antenna arrays. The AFE8030 simplifies calibration through integrated digital features, including TX NCO SWAP, RX NCO SWAP, and TX GAIN SWAP, RX GAIN SWAP. These functions can be controlled through GPIO signals or SPI commands using the C-SDK of the device.

As shown in Figure 5-6, during the RX antenna calibration, one TX channel can be rapidly re-configured to the uplink (RX) NCO frequency using the fast TX NCO SWAP function, and the transmitted signal is observed by all the RX channels simultaneously, based on the captured data, the RX antennal calibration coefficients are calculated and stored in FPGA. During this process, the RX DSA attenuation setting is also quickly switched to a higher value through the RX GAIN SWAP function so that the RX chain does not saturate due to the higher output from the TX Power Amplifier during the calibration mode. A similar process can be followed for TX antenna calibration by using the fast RX NCO SWAP and TX GAIN SWAP functions.

This approach provides a fast and elegant way for antenna calibration without introducing additional circuits on the board. By leveraging these built-in digital features, the AFE8030 enables a streamlined, hardware-efficient calibration architecture to meet the SWaP constraints of satellite payloads.