Patent US3042309A successfully refreshed from Google Patents.
Patent US4328499A successfully refreshed from Google Patents.
US4328499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio direction finding systems
Assignee: BAE Systems Electronics Ltd
•
Filing: 1979-10-24
•
Granted: 1982-05-04
•
Expires: 1999-10-24
Abstract
Abstract A radio direction finding system in which the angle of arrival of radio signals incident on a group of antenna elements is determined from the relative phase or phases of the radio signals incident upon two or more of said antenna elements. One of said elements is connected to a first radio receiver, while the other elements of the group are connected in turn to a second radio receiver, successive values of relative phase between signals received by the two receivers being utlized to derive a value for the angle of arrival of a radio signal relative to the antenna elements.
Inventors
- 👤 Donald W. Anderson
- 👤 Leonard J. Ogier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:34
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/02; G01S3/14; G01S3/46
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
154 words
A radio direction finding system of the kind in which radio signals incident upon spaced antenna elements from a predetermined sector are compared in phase and the value of phase difference is utilised to determine the angle of arrival of said radio signals with respect to said antenna elements, wherein there are provided two radio receiver arrangements and at least three spaced antenna elements aligned substantially in a common plane to receive radio signals from said sector, means to connect one of said receiver arrangements to receive radio signals from one only of said antenna elements and means to connect the other of said receiver arrangements to receive radio signals selectively from any one of the remaining antenna elements, and the angle of arrival of said radio signals is arranged to be determined from the respective phase differences between radio signals received by said one antenna element and by said other antenna elements respectively.
Claim 2
Dependent Claim
154 words
A radio direction finding system of the kind in which radio signals incident upon spaced antenna elements from a predetermined sector are compared in phase and the value of phase difference is utilised to determine the angle of arrival of said radio signals with respect to said antenna elements, wherein there are provided two radio receiver arrangements and at least three spaced antenna elements aligned substantially in a common plane to receive radio signals from said sector, means to connect one of said receiver arrangements to receive radio signals from one only of said antenna elements and means to connect the other of said receiver arrangements to receive radio signals selectively from any one of the remaining antenna elements, and the angle of arrival of said radio signals is arranged to be determined from the respective phase differences between radio signals received by said one antenna element and by said other antenna elements respectively.
Claim 3
Dependent Claim
26 words
A radio direction finding system in accordance with claim 1 in which signals representing said phase differences are digitally encoded and stored in digital storage means.
Claim 4
Dependent Claim
48 words
A radio direction finding system in accordance with claim 2 wherein said remaining antenna elements are connected in turn to said other receiving arrangement to provide a succession of phase difference signals from which a value for the angle of arrival of said radio signals may be derived.
Claim 5
Dependent Claim
24 words
A radio direction finding system in accordance with claim 1, claim 2 or claim 3 wherein there are provided at least five antenna elements.
Claim 6
Dependent Claim
25 words
A radio direction finding system in accordance with claim 1 wherein local oscillator signals for said radio receiver arrangements are generated by a frequency synthesizer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-03 | 1985-11-02 | 1986-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-03 | 1989-11-02 | 1990-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-03 | 1993-11-02 | 1994-05-04 | $7700.00 | Window Closed / Lapsed |