Pin-attenuator on waveguide-slot line

The characteristics of a pin-attenuator on a slotted-waveguide line, operating in the upper part of the cm-band, are presented. In the band of more than 3 GHz, an attenuator with two 2A5135 diodes provides an attenuation adjustment of up to 45 dB when the VSWR is no more than 2.2. While the attenuation adjustment is within 0-30 dB, the phase change is no more than 26/spl deg/.