With a modular design, a new traveling-wave-tube (TWT) amplifier provides convenient accessibility to all of its subassemblies. Dubbed the model 177, this amplifier spans 0.7 to 18 GHz and is designed for 0-dBm input level. It provides 10 kW at duty cycles to 5 percent and pulse widths of 0.1 to 100 s. The amplifier's RF output pulse width tracks the input 5-V video pulse. All of its power supplies are regulated, phase-shifted-resonant-mode, DC-to-DC converter designs operating at 50 kHz. Those power supplies boast full load efficiency greater than 90 percent.

In addition, a fast regulation loop response vows to provide minimal output variations at any pulse repetition frequency (PRF), including non-periodic and burst PRF. The amplifier's powersupply and power-line-related spurious signals fall below -50 dBc. With a four-line vacuum florescence display, the amplifier makes it easy for users to see its status as well as operating and heater time, TWT cathode and collector voltages, and helix and beam current. In addition, all of the parameters available at the front-panel display are available on a remote interface. Plug-in printed-circuit boards (PCBs) are available behind the front-panel door with test points and controls on the exposed edge of the boards. There is no exposed high voltage. Higher duty cycles or wider bandwidth are available upon request.

Applied System Engineering, Inc., 7510 Benbrook Pkwy., Fort Worth, TX 76126; (817) 249-4180, FAX: (817) 249-3413, www.applsys.com.

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