| 摘要 |
<p>974,682. Discharge tubes. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. March 13, 1962 [March 16, 1961], No. 9638/62. Heading H1D. In a noise generator for microwaves the microwave radiation produced in the positive column of a gas discharge is taken off by a waveguide 1, and the anode 7 of the gas discharge is part of the waveguide 1. The gas discharge between an oxide cathode 6 and the anode 7 is confined by a quartz tube 5 clamped in the waveguide 1 by springs 4. The waveguide 1 is surrounded by a glass envelope 9 with a molybdenum disc seal 8. A tuned diaphragm 11 to reduce reflection losses and a mica waveguide window 2 are provided. The filling is neon at a pressure of 20 cms. of mercury. The length of the positive column in the waveguide can be varied so that the equivalent noise temperature is equal to the electron temperature, and the noise energy is completely given up to the waveguide. A prior art device in which a gaseous discharge tube is disposed obliquely across a waveguide is referred to.</p> |
