Development of attenuators by carbon coating on APBN support rods using RF sputtering techniques

Abstract

There are chances of reflections of unwanted signal, due to several unavoidable reasons, in any working microwave tube. Due to this, the tubes do not give the desired performance. To minimise the chances of reflections the attenuators are used in microwave tubes. These attenuators may be used either inside or outside the tube depending upon its end use. For the fabrication of the attenuators in helix TWTs, the support rods are coated with controlled carbon layer with the specific profile and length using the specific processes. In this paper process of carbon coating on support rods using RF sputtering technique has been described in detail.