| 摘要 |
<p>MICROWAVE CAVITY TUNER In a microwave device, particularly a microwave local oscillator, frequency variations due to temperature changes are reduced by supporting the tuning element, for example a quartz or sapphire crystal, in the end of a tube of INVAR or other material having a low thermal coefficient of expansion. The tube projects into the cavity from a hole in one wall thereof. Preferably the tube is positively located relative to the cavity by means of an external lip on the tube abutting a shoulder formed by a reduced diameter part of the hold adjacent the cavity. The lip may be urged into positive contact with the shoulder by a spring washer acting between the end of the tube and the opposed end of a bush screwed into the hole.</p> |
