PTU
Photonic Transceiver Unit (PTU)
The Photonic Transceiver Unit (PTU) is a core module of the Optical Communications Terminal (OCT), designed for high-speed inter-satellite free-space optical communication. It supports bidirectional data transmission and optical beam tracking, serving as a key component for establishing stable and reliable optical communication links.
Key Features and Functions
Housed in a standard 2U rackmount chassis, the PTU integrates optical transmission, reception, and module control functions. On the transmit (Tx) side, high-speed communication data is modulated onto an optical carrier with an AM tracking tone to support beam tracking. On the receive (Rx) side, an avalanche photodiode (APD), signal amplification, and clock and data recovery (CDR) circuitry enable optical-to-electrical conversion and data recovery. An integrated microcontroller (MCU) provides parameter configuration, module control, and status monitoring.