The Overview
Empower RF Systems’ model 2236 liquid-cooled power amplifier is a commercial-off-the-shelf (COTS) system that combines the output of two 6-foot cabinets; each cabinet combines 16 2U power amplifiers. It pumps out up to 120 kW peak from 2,800 to 3,500 MHz.
Who Needs It & Why?
The model 2236 amplifier suits those looking for long-term reliability, high efficiency, and lower total cost of ownership in radar, test, and defense-electronics applications. According to the company, the unit offers more availability than traveling-wave-tube (TWT) and legacy solid-state implementations. Lower- and higher-power versions of this amplifier are available due to the scalable, modular design.
Under the Hood
The beating heart of the model 2236 is its amplifier subsystem drawers—32 in all, with 16 housed in each of two 3U 19-in. racks—each bearing multiple high-power, GaN-on-SiC power devices that provide wide frequency response, high gain, high peak power capability, and low distortion. Operating from 2,800 to 3,500 MHz, the flexible pulse-handling capabilities of this fielded system includes 20% duty cycles with pulse widths from 200 ns to 500 µs and pulse repetition frequencies (PRFs) up to 500 kHz.
Each of the system’s 32 subsystem drawers contains an integrated power supply within its 2U chassis; there's no separate system-level power supply. As a result, it’s impossible for the failure of an RF section or single power supply to take the entire system offline. Should a failure occur, it causes only a fractional reduction in total output power and the system at large remains functional.
Repair is a simple matter of sliding out the faulty drawer and sliding in a spare 2U PA drawer and 3U system controller, which can be done as a hot (optional) or muted swap in less than 15 minutes. Empower RF calls this system its Fast Field Replaceable design.
The class-AB amplifier is equipped to handle instantaneous pulse operation over the operating band. A built-in control and monitoring system provides protections such as duty-cycle and pulse-width protection, which can be selected to back off the system’s output power when maximum limits are violated. Power is then immediately dropped by 10 dB and stays that way until normal operation persists for at least five pulses. Thus, there’s no change to the pulse shape after the first detected violation.
Droop protection is available as an option. Contact Empower RF on the capability of digitally modulated signals on the pulse carrier.
