| 摘要 |
1,208,093. Phase shifters. C.S.F. COMPAGNIE GENERALE DE TELEGRAPHIE SANS FIL. 21 April, 1969 [19 April, 1968], No. 20156/69. Heading H1W. [Also in Division H4] An aerial comprises a rectangular waveguide G which has an array of transverse slots F 1 , F 2 , F 3 , ... in one broad wall which are spaced apart by #/4 (# = guide wavelength at mean operating frequency). Inside the guide is a longitudinal strip R of ferro-electric material in which there is a longitudinal hole containing a conductive wire or strip C. Power is fed at one end of the waveguide, and a matching load is provided at the other, so that the array of slots radiates. A variable D.C. voltage may be applied from a source S to polarize the strip R and change its permittivity. This alters the velocity of propagation in the waveguide and, consequently, the phase shift between slots, so that the directivity of the aerial is changed. The waveguide may be operated in a TE mode or in the TEM mode. The strip R may be made from a powder of mixed barium-strontium titanites in suspension in P.T.F.E. The different Curie points of the titanite components enable operation over a wide temperature range. In a second embodiment slots in a broad wall of a rectangular waveguide are angled obliquely, with adjacent slots oppositely angled, the slot spacing being #/2 (Fig. 2, not shown). In a third embodiment a conductive strip is placed on the upper part of a ferro-electric strip (Fig. 4, not shown). In a fourth embodiment, a ferroelectric strip comprises several layers, each layer having a different Curie point (Fig. 5, not shown). In a fifth embodiment, instead of a strip of ferro-electric material a series of longitudinally spaced blocks having various Curie points is arranged under a conductive strip (Fig. 6, not shown). |
