GB1485491A - Antenna systems - Google Patents

Abstract

1485491 Aerials SIEMENS AG 22 Aug 1974 [23 Aug 1973] 36877/74 Heading H4A The Specification describes a phase controlled antenna system having a plurality of elements arranged in one plane in rows and columns wherein adjustment of the phase supplied to the elements is by electronically variable digital phase shift devices, and is of the kind described in Specification 1,333,479. Although the embodiment described relates to a radiation fed system as in the Specification referred to, it is stated that the invention may be related to other phase-controlled antenna systems and also to a radiation-fed monopulse system wherein two or four feeder horns are used. In the present invention, the focusing phase values ## required to produce transmission of a plane wave beam at any given operating frequency are stored in an accumulator group store, so that the focusing phase ## may be called up for any frequency desired whilst the deflection phase values # a required for a specific beam direction are computed in a common phase computer for each antenna element, each individual phase shift device being provided with a device for adding the particular value of ##, which has been called up, to the computed value of # a for the associated antenna element. Several arrangements of the actual disposition of elements on the planar array are given, Fig. 6 (and Figs. 3-5, not shown), wherein the number of phase shift devices are thinned out with respect to the homogeneous array (Fig. 3), In Fig. 6, the radiation from feed horn 6 falls on a smaller area, homogeneous array 6, while the radiating elements are thinned out and occupy a larger area. A phase computing arrangement is described with regard to an arrangement such as Figs. 1 or 6 (or Fig. 3). In Fig. 7, guidance data from a central computer containing horizontal and vertical deflection data and operating frequency data, is converted in control data generator 20 into control data signals, which are applied to a phase computer 21 consisting of a vertical computer 22 and horizontal computers as described in Specification 1,333,479, but there is in addition included an accumulator group 24 and an adder group 25. The respective deflection phase signals #a from 23 are added to the respective focusing phase signals ##, which are stored in accumulator 24 and called up in response to frequency signal F, in a respective adder 25, located at each digital phase shift device 26 associated with each antenna element, which arrangement is stated to reduce the complexity of the phase computer.