Status of a high-frequency harmonic amplifier's development

Summary form only given, as follows. The harmonic amplifier (HARA) is a very compact, high efficiency amplifier that has been under development at Microwave Technologies in the past few years. The HARA uses a two-cavity system in conjunction with a spiraling beam to produce high-frequency radiation. In this paper we will review C-band, Ka-band and W-band HARA experiments currently underway at Microwave Technologies. We will also present initial results for the C-band amplifier's development, where a 7 kV, 100 mA pencil electron beam is used to drive a novel output cavity for the production of microwave output power. The HARA is very compact (/spl sim/3-inches long) and does not require a beam focusing system. This makes for a lightweight system which is well suited to applications where size, weight and efficiency are critical.