| 摘要 |
1,137,350. Valve oscillating circuits. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 27 Sept., 1967 [29 Sept., 1966], No. 43940/67. Heading H3F. A self-excited velocity modulation tube generator-which appears as parallel-connected inductance L Gen , Fig. 1, capacitance C GEN and resistance R Gen -is coupled to a variable load V via a substantially loss-free waveguide of length equal to or greater than where Q EGen is the external Q factor of the generator, # 0 is the wavelength in free space, and #w the wavelength in the waveguide, at the mean generator frequency, and S max is the maximum permissible standing-wave ratio of the generator. The arrangement is intended for use in dielectric heating apparatus, to prevent operation occurring in the region of generator instability. In an embodiment the material to be heated, 3, Fig. 2, is contained in an enclosure 3 which is coupled to the generator Gen via slot 5 and a long rectangular waveguide Hl; the generator Gen is coupled in by means of probe 4 situated a quarter-wavelength from the closed end of the waveguide. Adjustment for high efficiency is performed by means of a stud 7 adjustable as to its extension within the waveguide. |
