Dual polarization electromagnetic power reception and conversion system

• US 4,943,811 A
• Filed: 11/23/1987
• Issued: 07/24/1990
• Est. Priority Date: 11/23/1987
• Status: Expired due to Term

• Current Assignee: Her Majesty The Queen In Right of Canada As Represented By The Minister of National Defence
• Original Assignee: Canadian Patents and Development Limited
• Inventors: Alden, Adrian W., Jull, George W., Ohno, Tom T.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Wise, Robert E.
• Application Number:
  US07/124,159
• Time in Patent Office: 974 Days
• Field of Search: 343/795, 343/798, 343/801, 343/810, 343/812, 343/814, 343/815, 343/817, 343/818
• US Class Current: 343/814
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H01Q 21/062 using dipole aerials; H01Q21/067, H01Q21/068 take precedence
• CPC Class Codes: H01Q 25/001 Crossed polarisation dual antennas orthomode horns H01Q13/0258; cross-polarised rear feeds H01Q19/136; orthomode transducers H01P1/161
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/27 characterised by the type of receiving antennas, e.g. rectennas
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas

Abstract

An antenna array for receiving dual polarized electromagnetic waves, comprised of a first thin-film printed circuit rectenna having a plurality of linear half-wavelength dipole antennae oriented in a first direction for receiving a first component of the dual polarized waves, and a second thin-film printed circuit rectenna parallel to the first rectenna, having a plurality of linear half-wavelength dipole antennae oriented in a second direction for receiving the second orthogonal component of the electromagnetic waves. A reflector screen is disposed parallel and behind the second rectenna, for reflecting incident electromagnetic waves transmitted through the first and second rectennae back to the first and second rectennae for reception thereby. The dipole antenna of the first rectenna are disposed in a predetermined pattern in relation to the second rectenna dipole antennae, the first and second rectennae are separated by one of either substantially zero distance or by a multiple half-wavelength distance, and the second rectenna and reflector screen are separated by a predetermined distance to effect substantial cancellation of transmission line shielding effects and mutual coupling, resulting in high efficiency signal reception.

Claims

1. An antenna aray for receiving a beam of dual polarized electromagnetic waves, comprised of:

(a) a first rectenna formed from a first plurality of dipole antenna elements connected to a first plurality of transmission lines orthogonal to said antenna elements, for receiving and carrying a first polarization component of said electromagnetic waves, said first plurality of transmission lines being characterized by a predetermined inductive reactance,

(b) a second rectenna parallel to said first rectenna and formed from a second plurality of dipole antenna elements oriented orthogonally to said first plurality of antenna elements, and connected to a second plurality of transmission lines orthogonal to said second plurality of antenna elements, for receiving and carrying a second polarization component of said electromagnetic waves orthogonal to said first component, said second plurality of transmission lines also being characterized by said predetermined inductive reactance.

(c) a reflector plane parallel to said second rectenna for reflecting incident electromagnetic waves transmitted through said first and second rectennae back to said first and second rectennae for reception thereby,

(d) said first and second rectenna being separated by a first predetermined distance given by mλ

/2, where m is a whole number and λ

is the wavelength of said electromagnetic wave,

(e) said second rectenna and reflector plane being separated by a second predetermined distance sufficient for causing the capacitive reactance of free space between said second rectenna and said reflector plane to be equal and opposite to said predetermined inductive reactance of said first and second pluralities of transmission lines, and

(f) said first and second pluralities of dipole antenna elements and transmission lines conforming to a predetermined alignment with respect to each other wherein respective first lines disposed mid-point between respective rows of said transmission lines of the first rectenna are colinear when viewed along said beam with respective dipole antenna elements on said second rectenna, and further lines disposed orthogonal to said first lines and passing midway between successive ones of said dipole antennae of the first rectenna, and further lines disposed orthogonal to said first lines and passing midway between successive ones of said dipole antenna of the first rectenna are parallel to and midway between respective rows of transmission lines of said second rectenna when viewed along said beam, whereby said first and further lines intersect to form a plurality of independent transmission line cells enclosing respective pairs of said dipole antennae of said first rectenna, such that the effect of said predetermined inductive reactance due to said second and first pluralities of transmission lines is compensated for, and the directivity of said array is characterized by the directivity of each of saId cells, thereby resulting in high efficiency reception of said beam of dual polarized electromagnetic waves over a wide range of angles of incidence of said beam on said array.

2. An antenna array as defined in claim 1, wherein each of said first and second thin-film printed circuit rectennae is further comprised of:

(a) a plurality of wave filters connected to said transmission lines, for filtering said received first and second components of said electromagnetic wave carried by said busses; and

(b) a plurality of rectifier diodes connected to said transmission lines and said wave filters, for rectifying said received and filtered components carried by said transmission lines, and in response generating an output power signal.

3. An antenna array as defined in claim 1, wherein said first and second rectennae and said reflector plane are separated by predetermined amounts sufficient to capacitively balance any inductance caused by said transmission lines.

4. An antenna array as defined in claim 1, wherein m=0, and second rectennae, thereby enabling conformal application of said rectennae to a curved surface.

5. An antenna array for receiving dual polarized electromagnetic waves comprised of:

(a) a first plurality of parallel oriented thin-film printed circuit rectennae formed from a first plurality of linear half wavelength dipole antennae for receiving a first component of said electromagnetic waves, each of said rectennae of said first plurality being separated by a distance equivalent to a predetermined number of multiples of one half of the wavelength of said electromagnetic waves,

(b) a second plurality of thin-film printed circuit rectennae oriented in parallel with said first plurality of rectennae and formed from a second plurality of linear half wavelength dipole antennae for receiving a second component of said electromagnetic waves orthogonal to said first component, each of said rectennae of said second plurality being separated by a distance equivalent to said predetermined number of multiples of one half of the wavelength of said electromagnetic waves,

(c) a reflector screen parallel and adjacent to said second plurality of rectennae, for reflecting incident electromagnetic waves transmitted through said first and second rectennae back to said first and second rectennae for reception thereby, and

(d) said first and second pluralities of rectennae being comprised of a plurality of DC power collection transmission lines characterized by a predetermined inductive reactance, for interconnecting said first and second pluralities of dipole antennae, said first and second pluralities of rectennae conforming to a predetermined alignment wherein respective first lines disposed mid-point between respective rows of said transmission lines of said first plurality of rectennae are colinear when viewed along said beam with respective dipole antenna elements on said second plurality of rectennae, and further lines disposed orthogonal to said first lines and passing midway between successive ones of said dipole antennae of the first plurality of rectennae are parallel to and midway between respective rows of transmission lines of said second plurality of rectennae when viewed along said beam, whereby said first and further lines intersect to form a plurality of independent transmission line cells enclosing respective pairs of said dipole antennae of said first plurality of rectennae, such that the directivity of said array is characterized by the directivity of each of said cells, and said reflector screen being separated from a closest adjacent one of said second plurality of rectennae by a predetermined distance sufficient for causing the capacitive reactance of free space between said closest adjacent one of the second plurality of rectennae and said reflector plane equal and opposite to said predetermined inductive reactance of said transmission lines, for cancelling mutual inductance between said rectennae, resulting in high efficiency reception of said waves over a wide range of angles of incidence of said waves on said pair of rectennae.

6. An electromagnetic energy transmission, reception and conversion system, comprised of:

(a) means for generating and transmitting a beam of dual polarized electromagnetic waves,

(b) a moving vehicle,

(c) a pair of parallel rectennae and a reflector screen mounted on said vehicle, for receiving and converting said beam of electromagnetic waves to electric power for use on said vehicle,

(d) said pair of rectennae being separated by a distance of mλ

/2, where m is a whole number and λ

is the wavelength of said electromagnetic waves, each said pair of rectennae being comprised of a plurality of DC power collection transmission lines characterized by a predetermined inductive reactance, for interconnecting a plurality of dipole antenna elements, and a plurality of wave filters and rectifiers for filtering and rectifying said received beam and in response generating said electric power,

(e) said pair of rectennae being oriented with respect to each other according to a predetermined alignment of a first plurality of lines parallel to and midway between said transmission lines on a first one of said rectennae with a second plurality of lines parallel to and midway between said dipole antenna elements of the other of said rectennae, and alignment of a third plurality of lines perpendicular to and midway between said dipole antenna elements of said other rectenna with a fourth plurality of lines parallel to and colinear with the dipole antenna elements of said first one of the rectennae, and said reflector screen being parallel to and separated from a closest adjacent one of said rectennae by a predetermined distance sufficient for causing the capacitive reactance of free space between said closest adjacent one of the rectennae and said reflector plane to be equal and opposite to said predetermined inductive reactance of said transmission lines for cancelling mutual inductance between said pair of rectennae, resulting in high efficiency reception of said beam over a wide range of angles of incidence of said beam on said pair of rectennae.

7. An electromagnetic energy transmission, reception and conversion system as defined in claim 6, wherein said means for generating and transmitting said beam of dual polarized electromagnetic waves is comprised of a microwave transmitter.

8. An electromagnetic energy transmission, reception and conversion system as defined in claim 6, wherein said vehicle is an aircraft with said rectennae being mounted on an undersurface thereof, means being provided on said aircraft for receiving said electric power and in response propelling said aircraft.

9. An electromagnetic energy transmission, reception and conversion system as defined in claim 8, wherein said rectennae and said reflector screen are conformally applied to the undersurface of respective wings of said aircraft.

10. An electromagnetic energy transmission, reception and conversion system as defined in claim 6, wherein said plurality of dipole antenna elements and D.C. power collection transmission lines are arranged in a square array.

11. An electromagnetic energy transmission, reception and conversion system as defined in claim 6, wherein said vehicle further includes electrically powered payload, said electric power being applied to operation of said payload.