A high average power, 30% bandwidth, traveling-wave amplifier

The Hughes Microwave Tube Division has recently achieved 30% bandwidth in a periodically focused, traveling-wave amplifier which delivers in excess of several kilowatts output power with 43 db gain. The circuit employed is a variation of the coupled cavity structure. Hence, this development represents the first successful combination of a wide bandwidth, usually associated with the fragile helix circuits, and the power handling ability of the coupled cavity approach. The performance of this device is unique in that useful gain is achieved over almost the entire cold pass band of the circuit. Although the full capabilities of this slow wave structure are not yet known, recent experimental results indicate the possibility of 60% bandwidths at any frequency from L-Band to K-Band.