GB542535A - Improvements in phase shifting networks applied to directive antenna systems - Google Patents

Abstract

542,535. Directive wireless signalling. STANDARD TELEPHONES & CABLES, Ltd. Aug. 3, 1940, No. 12559. Convention date, Aug. 3, 1939. [Class 40 (v)] [Also in Group XXXVI] The directive properties of an aerial are improved by constructing it in the form of two radiant conductors interconnected by a phaseshifting means comprising two condensers in conjugate relation with respect to the operating frequency. Fig. 8 shows the invention applied to a V-antenna comprising arms 80, 81, the radiation patterns of which are shown at 83, 83<SP>1</SP>. By the inclusion of phase advancing networks 82, each comprising a pair of equal condensers spaced apart by a distance of one quarter wavelength plus the shift due to one of the condensers, the radiation pattern is altered to 84, 841 giving a considerably greater amount of radiant energy in the desired direction. Arrangements are also described involving the use of two pairs of condensers in each limb of the antenna and in an array comprising a double V. Fig. 10 shows a construction of condenser comprising coaxial cylindrical plates 53, 54 mounted so as to be relatively adjustable on the shank of a strain insulator 50. leads 55, 56 serving to connect the condenser to the sections of the antenna. In a modification the condenser plates are in the form of opposed flat discs with rolled edges. Specification 493,235 is referred to.