EP0469741A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Radio frequency apparatus
Assignee: Microsemi Frequency and Time Corp
•
Filing: 1991-07-16
•
Granted: —
•
Expires: 2011-07-16
Abstract
Abstract A quadrifilar radio frequency antenna intended primarily for receiving signals from an earth orbiting satellite for navigation has four helical wire elements (10A-10D) shaped and arranged so as to define a cylindrical envelope (12). The elements (10A-10D) are co-extensive in the axial direction of the envelope and are mounted at their opposite ends in two printed circuit boards (16, 17) lying in spaced apart planes perpendicular to the axis (14) with the end parts of the elements being soldered to conductor tracks on the boards (16, 17), the tracks constituting impedance elements between the helical elements (10A-10D) and between the helical elements and (10A-10D) and an axially located coaxial feeder (18). The conductor tracks are such that the effective length of one pair (10A, 10B) of helical elements and associated impedance elements is greater than that of the other pair (10C, 10D) and associated impedance elements. In this way, phase quadrature between the two pairs is obtained at the operating frequency without using differently shaped helical elements, and with little or no adjustment of the elements in the manufacturing process.
Inventors
- 👤 Sidney John Branson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 01:14
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/36; H01Q1/362; H01Q11/00; H01Q11/02; H01Q11/08
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
39 words
A radio frequency antenna comprising a plurality of helical elements arranged around a common axis, a substantially axially located feeder structure, and a plurality of separately formed coupling elements forming conducting paths between the helical elements and the axis.
Claim 2
Dependent Claim
39 words
A radio frequency antenna comprising a plurality of helical elements arranged around a common axis, a substantially axially located feeder structure, and a plurality of separately formed coupling elements forming conducting paths between the helical elements and the axis.
Claim 3
Dependent Claim
18 words
An antenna according to claim 1, wherein the coupling elements are located at ends of the helical elements.
Claim 4
Dependent Claim
26 words
An antenna according to claim 2, wherein the coupling elements include radially extending conductors connecting the said ends of the helical elements to the feeder structure.
Claim 5
Dependent Claim
15 words
An antenna according to claim 3, wherein the radially extending conductors have different electrical lengths.
Claim 6
Dependent Claim
17 words
An antenna according to any preceding claim, wherein the coupling elements include elements of different electrical impedances.
Claim 7
Dependent Claim
42 words
An antenna according to claim 5 having at least two pairs of helical elements, wherein the coupling elements associated with a first of the pairs include elements of a different electrical impedance from corresponding coupling elements of a second of the pairs.
Claim 8
Dependent Claim
30 words
An antenna according to any preceding claim, further comprising at least one electrically insulative mounting member extending perpendicularly to the axis, the helical elements being supported by the said member.
Claim 9
Dependent Claim
27 words
An antenna according to claim 7, wherein the insulative member comprises a printed circuit board, and wherein the coupling elements are conductive tracks formed on the board.
Claim 10
Dependent Claim
23 words
An antenna according to claim 8, wherein the printed circuit board is mounted on the feeder structure, which extends along the common axis.
Claim 11
Dependent Claim
21 words
An antenna according to any preceding claim, wherein each helical element executes substantially a half turn around a notional cylindrical envelope.
Claim 12
Dependent Claim
34 words
An antenna according to any preceding claim, having four of the said helical elements all substantially identical to each other and centred on the common axis, the elements being co-extensive in the axial direction.
Claim 13
Dependent Claim
49 words
An antenna according to claim 8 or claim 9, having four of the said helical elements all substantially identical to each other and centred on the common axis, each element having one end secured to one printed circuit board and its other end secured to another printed circuit board.
Claim 14
Dependent Claim
77 words
An antenna according to claim 12, wherein the printed circuit boards include a board having four conductor tracks extending radially with respect to the common axis, each track being electrically connected to a respective one of the elements, the four tracks comprising two track pairs with the tracks of each pair extending in opposite directions with respect to each other, and wherein the tracks of one pair have different electrical lengths from those of the other pair.
Claim 15
Dependent Claim
53 words
An antenna according to claim 13, wherein the feeder structure comprises a coaxial feeder line having an inner conductor and an outer conductor, and wherein, for each of the said track pairs, one of the associated helical elements is coupled to the inner conductor and the other is coupled to the outer conductor.
Claim 16
Dependent Claim
18 words
An antenna according to claim 9, wherein the feeder structure is a semi-rigid or rigid coaxial feeder line.
Claim 17
Independent Claim
152 words
A method of making a radio frequency antenna which has a plurality of helical elements arranged around a common axis, a substantially axially located feeder structure, and at least two mounting members, at least one of which is insulative and bears coupling elements forming radio frequency conductive paths between the helical elements and the axis, wherein the method comprises: locating the helical elements with their axes coincident and with their respective ends lying in two spaced apart planes perpendicular to the common axis; securing a first of the mounting members to the helical element ends in one of the planes; bringing together the second of the mounting members and the assembly of the first mounting member and the helical elements so that the second mounting member is in a predetermined position parallel to and axially spaced from the first mounting member in which it is located on the other ends of the
Claim 18
Independent Claim
152 words
A method of making a radio frequency antenna which has a plurality of helical elements arranged around a common axis, a substantially axially located feeder structure, and at least two mounting members, at least one of which is insulative and bears coupling elements forming radio frequency conductive paths between the helical elements and the axis, wherein the method comprises: locating the helical elements with their axes coincident and with their respective ends lying in two spaced apart planes perpendicular to the common axis; securing a first of the mounting members to the helical element ends in one of the planes; bringing together the second of the mounting members and the assembly of the first mounting member and the helical elements so that the second mounting member is in a predetermined position parallel to and axially spaced from the first mounting member in which it is located on the other ends of the
Claim 19
Dependent Claim
24 words
helical elements; securing the said other mounting member to the said other ends; and attaching the feeder structure to one or both mounting members.
Claim 20
Dependent Claim
24 words
helical elements; securing the said other mounting member to the said other ends; and attaching the feeder structure to one or both mounting members.
Claim 21
Dependent Claim
49 words
A method according to claim 16, including the step of locating the helical elements around a cylindrical mandrel with one end of each element projecting beyond an end of the mandrel, and holding the elements on the mandrel while the first mounting member is secured to the projecting ends.
Claim 22
Dependent Claim
58 words
A method according to claim 17, in which the assembly of the helical elements and the first mounting member is held in a jig having two parts slidable relative to each other, the first mounting member being fitted in one of the jig parts and the second mounting member being fitted in the other of the jig parts.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.