| 摘要 |
971,034. Waveguides. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. Nov. 13, 1962 [Nov. 17, 1961], No. 42783/62. Heading H1W. A mode filter for use in a waveguide channel utilizing the circular-electric H 01 mode of propagation comprises a circular helical winding MF of insulated wire which tapers from both ends towards the centre. The filter joins two circular waveguides A 1 , A 2 which may have equal or unequal diameters. A central portion a of uniform diameter may have a length from five to ten times the longest wavelength to be propagated. The ratio of the diameter of this portion to that of the guides A 1 , A 2 is preferably about 0.6. The wire winding may be embedded in attenuating material. It is preferably wound upon a splitable former and covered with alternate layers of glass fabric and moulded resin. A single or multiple-start helix of enamelled wire may be used. |
