The model AT-A69 250 Watt Attenuator is designed using a broadband high power low PIM precision directional coupler that is terminated with a long length of low PIM cable on the main line. Using this design technique, the attenuation accuracy is determined by the directional coupler. In additional, high input powers are dissipated in the long length of low PIM cable with minor changes in return loss. The effect of power and temperature changes are isolated from the output of the attenuator due to the directivity of the coupler. The result is a highly accurate level of attenuation that is stable with changes in power and temperature.
The low PIM cable load encased in a forced air cooled chassis with an integrated fan. The inherent structure provides robust protection from overpowering conditions such as a short or open connection. Attenuator values of 10 dB, 20 dB, and 30 dB are available. A 6-foot power cord is included with an on-off switch to power a cooling fan (North American or European versions available). A complete data sheet is available in the Attenuator section under part number AT-A69