Dual mode phased array antenna system
US4989011A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1987 |
| Grant date | Jan 29, 1991 |
| Priority date | — |
| Expiry date | Oct 23, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q3/40
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
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 use…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.