Study on a Novel Directional Coupler for Rapid Power Measurement of the W band Gyro-TWT

A study of a novel directional coupler for measuring the output power of a W-band gyro-TWT has been presented. The designed directional coupler is a three ports device, in which, the multi-apertures with different diameters have been arranged in two rows. By using it, the rapid power measurement for the W-band TE01 mode gyro-TWT has been achieved. The measurement result indicates that the coupling coefficient of the directional coupler is between -50dB and -56dB with the bandwidth of 6GHz, which agrees well with the simulation result. In additional, the influence of the arrangement method of the apertures on the coupling coefficient has also been analyzed.