GB519350A - Directional radio antenna arrays - Google Patents

Abstract

519,350. Aerials; directive wireless signalling. STANDARD TELEPHONES & CABLES Ltd. Oct. 14, 1938, No. 29838. Convention date, Dec. 6, 1937. [Class 40 (v)] Three or more frame aerials are so arranged as to reduce radiation in one plane and increase it in the other. As shown in Fig. 3, the aerial ABCD is directly energized and excites the two side aerials FGHE and IJKL by induction. The upper and lower horizontal limbs of all the aerials then combine to give three times more radiation in the direction OY than the two vertical limbs, FG and LK, give in the direction OX, the radiation from the remaining vertical limbs EH, DA and CB, IJ being cancelled because of their close proximity to each other. The arrangement shown in Fig. 3 may be duplicated to give an horizontal array with two directly-energized aerials and four associated aerials, the latter being fed by induction. In Fig. 5, the two central aerials are voltagefed as shown, the two outer aerials being excited by induction. The radiation in the direction OY is then four times that in the direction OX. In all cases, waves travelling in the direction OY are polarized in the plane OX, and vice versa. In Fig. 7, the two crossed lower frames are directly energized in phase-quadrature, and the upper crossed pair by excitation from the lower, to give a rotating field which is uniformly distributed in space. This arrangement is stated to be suitable for transmitting (or receiving) television signals, and to be free from " night-effect." The two outer frames in Fig. 3 may be keyed to produce an " overlapping- beam effect. The directional properties of the frame-aerial combination may be utilized for the navigation and blind landing of aeroplanes, and for the detection of a distant aeroplane which reflects an outgoing beam.