The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 29, 1991
Filed:
Oct. 23, 1987
Harold A Rosen, Santa Monica, CA (US);
James D Thompson, Manhattan Beach, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A phased array antenna system (20; 120) having an array (22; 122) of radiating elements (24-30; H1-H32), such as pyramidal horns, and a distribution network (32; 124) connected thereto, has a dual mode of operation where each mode produces a composite beam which can and preferably does produce an identical far-field electromagnetic radiation pattern. The first composite beam is made up of a plurality of individual beams, forming a linear combination of excitation coefficients (a.sub.1 -a.sub.4) that are mathematically orthogonal to the linear combination of excitation coefficients (b.sub.1 -b.sub.4) of the individual beams of the other composite beam. A plurality of input ports (42-44; 176-178) are provided, and each composite beam is associated with an information-bearing input signal applied to one of the input ports. The distribution network (32; 124) is preferably constructed with at least two stages of signal-dividing devices (52-58; 222-228, 270-282) such as directional couplers and at least a pair of phase-shifting devices (60-62; 230-232, 284-296). By using passive devices, the distribution network (32; 124) is substantially lossless and reciprocal, and can thus also be used for dual mode reception of two distinct beams.