300 MILLIWATT X-BAND TRIODE OSCILLATOR.
Final rept. 1 Dec 65-30 Apr 68,
GENERAL ELECTRIC CO OWENSBORO KY TUBE DEPT
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Mechanically tuned triode-in-cavity oscillators covering the frequency range from 8.850 to 9.170 GHz were successfully demonstrated during this program. Highest CW power output obtained was 750 milliwatts with 600 milliwatts a typical value in the final models. The target objective was a minimum output of 300 milliwatts. Electronic tuning by means of varactor diode was not practical in the circuits evaluated because of inadequate tuning range and excessive power output loss. Heat generated by an anode dissipation of 15 watts prevented location of the varactor in the most effective circuit position, such as in close proximity to the grid-to-anode gap, and thereby minimized the effect of capacitance change of the varactor on the frequency. Operational life was generally less than required. Best operational life of 265 hours duration was obtained from a triode having a nickel base cathode and a novel interwoven grid structure. Failure mechanism is an increase in effective Mu because of film formation on grid surfaces and a decline in the required peak cathode emission. Eight triode designs and five cavity designs were evaluated during the program. Author
- Electrical and Electronic Equipment