The millimeter-wave extended interaction oscillator

The theory and operation of the extended interaction oscillator (EIO) are presented. Details of an initial feasibility study at X-band are given. This study proved the practicality of using a space-charge focused electron beam, and provided AM and FM noise data. A space-charge focused K
a
-band EIO, which produced 25 watts at 42.5 Gc/s, is described. A prediction of the output power and efficiency obtainable from both space-charge focused and permanent magnet focused EIO's, vs. frequency, is presented.