Study of high power, two-stage, TWT X-band amplifier

Summary form only given. A disk loaded slow wave structure with a cold wave phase (without electron beam) velocity of the TM/sub 01/ wave greater than the speed of light (1.05c) is used as the electron bunching stage of a two stage X-band amplifier. The high phase velocity section produces well defined electron bunches. The second section, where the cold wave phase velocity is (0.84c), i.e. less than beam velocity of 0.91c, is used to generate the high output power microwave radiation. The tightly bunched beam from the high phase velocity section enhances the beam energy conversion into microwave radiation compared to that obtained with a synchronous electron-wave buncher. A new: amplifier with similar phase velocity characteristics but with a 1 GHz bandwidth and an HEM/sub 11/, TM/sub 01/ mode frequency separation of 3.3 GHz has been designed and constructed. The interaction frequency for the HEM mode is above the passband of the TM mode. Testing is in progress. The performance of the new amplifier will be compared with results obtained using the earlier configuration.