Active Antenna Unit (AAU)

Overview

The Active Antenna Unit (AAU) fuses the antenna array and the radio electronics into one weatherproof, pole-mounted package. It carries a 64-element dual-polarized array, 64 transmit/receive chains, RF filtering and the beamforming controller, eliminating the lossy coaxial feeders that separate radios once required.

Construction

The array sits behind a Radome Cover, a fiberglass cover transparent to RF that protects the Antenna Array PCB from weather. Each array channel is driven by a T/R Module pairing a GaN power amplifier with a low-noise receive amplifier and a digital phase shifter. Transmit and receive bands are separated by the cavity-based RF Filter / Duplexer Bank. Steering weights for every element are computed by the Beamforming ASIC Board, while the Calibration Network continuously samples each channel so amplitude and phase stay matched across the array, a prerequisite for accurate beams. The electronics are sealed inside the AAU Weatherproof Enclosure, a die-cast IP65 shell, and waste heat is shed passively through the AAU Heatsink Fins fins, avoiding fans that would compromise the weather seal.