WO2003001625A1

WO2003001625A1 - Waveguide assemblies

Info

Publication number: WO2003001625A1
Application number: PCT/GB2002/002737
Authority: WO
Inventors: John Louis Frederick Charles Collins
Original assignee: FORTEL TECHNOLOGIES Inc
Current assignee: FORTEL TECHNOLOGIES Inc
Priority date: 2001-06-20
Filing date: 2002-06-13
Publication date: 2003-01-03
Anticipated expiration: 2003-12-20
Also published as: GB0115029D0

Abstract

There is described a waveguide assembly made up of first and second generally planar components formed of a insulating material coated on one side with a conducting material. When the first and second components are placed face to face, closed metallic channels are formed to act as waveguides. Electrically conductive tracks formed on the members act as a bias voltage structure. The members are moulded plastics members formed for example by injection moulding or vacuum forming.

Description

"Waveguide Assemblies"

This invention relates to waveguide assemblies and is particularly, but not exclusively applicable to waveguide assemblies for use as phased arrays.

It is known to provide a phased array for use, for example, as a microwave antenna by providing a waveguide assembly having appropriate physical dimensions and positioning phase shifting components at specified locations within the assembly. To achieve controlled phase shift, it is also necessary to apply a bias voltage to the phase shifting components.

Known waveguide assemblies of this type are complex and expensive, involving the machining of metal components and the provision of wiring to distribute the bias voltage.

The present invention provides a waveguide assembly comprising first and second generally planar components formed of an insulating material coated on one side with a conductive material; at least one of the first and second components being formed with channels which are open to the side coated with the conductive material such that, when the first and second components are placed face-to-face, closed metallic channels are formed to act as waveguides; the assembly further including a bias voltage structure comprising electrically conductive tracks formed on one of the first and second members and separated from the metallic coating of the said one member by an insulating layer, and an insulating layer formed on the other of the first and second members in locations to overlie the conductive tracks.

Preferably, the first and second members are moulded plastics members, for example injection moulded, or vacuum formed.

The metallic coating is preferably formed by electroless copper plating to provide a continuous copper layer, typically 3 microns thick.

The insulating layers and metallic tracks may suitably be in the region of 0.1 microns thick.

The invention further provides a phased array for microwave radiation, comprising a waveguide assembly as defined above, and a plurality of phase shifting components disposed with the waveguide channels at predetermined locations, said conductive tracks extending into said waveguide channels at said predetermined locations for connecting a bias voltage to the phase shifting components.

An embodiment of the invention will now be described, by way of example, with reference to the drawings, in which:

Fig. 1 is an exploded perspective view of part of one form of waveguide assembly in accordance with the invention; Fig. 2 is a cross-section through part of the assembly of Fig. 1; and Fig. 3 is a schematic perspective view of part of a phased array utilising the assembly of Fig. 1.

Referring to Figs. 1 and 2, a waveguide assembly comprises a first generally planar member or upper sheet 10, and a second generally planar member or lower sheet 12. The upper sheet 10 is formed to define an open channel 14, and the lower sheet 12 is likewise formed to define an open channel 16. When the two sheets 10, 12 are abutted face-to-face the channels 14, 16 form a closed channel defining a waveguide which, in known fashion, has transverse dimensions suitable for propagating a predetermined frequency and form of microwave radiation.

As best seen in Fig. 2, the sheets 10 and 12 comprise a shaped plastics base 20 having one surface metallised at 22. The base 20 is moulded from a suitable plastics material, suitably by injection moulding or, as in the present embodiment, vacuum moulding a thin rigid sheet.

The metallisation 22 in this embodiment is copper with a thickness of 3 microns deposited by, for example, electroless plating.

A conductor network is provided within the assembly as follows. An insulation substrate 24, 0.1 micron thick, is deposited on the lower sheet 12 on top of the metallisation 22. A conductive substrate 26, 0.1 micron thick, is deposited on top of and centrally within the width of the insulation substrate 24. A matching insulation substrate 28, 0.1 micron thick, is deposited on the upper sheet 10 on top of the metallisation 22.

The insulation substrates 24 and 28 and the conductive substrate 26 can be deposited by processes known in the production of integrated circuits and printed circuit boards. It is convenient to form the various layers 22 - 28 on flat sheets before these are moulded, but alternatively the layers may be laid down after the sheets are moulded.

Thus when the sheets 10 and 12 are secured together a conductive network is present within the array with a conductor exposed at predetermined locations within the waveguide channels, as at 30. Fig. 3 shows schematically part of a phased array formed using the above assembly. The phased array has waveguide passages 32 containing phase shifting components indicated at 34 which are connected via the conductive network 36 to a source of bias voltage which can be used to control the phase shift.

Modifications and improvements may be made to the foregoing within the scope of the present invention.

Claims

1 A waveguide assembly comprising first and second generally planar components formed of an insulating material coated on one side with a conductive material; at least one of the first and second components being formed with channels which are open to the side coated with the conductive material such that, when the first and second components are placed face-to-face, closed metallic channels are formed to act as waveguides; the assembly further including a bias voltage structure comprising electrically conductive tracks formed on one of the first and second members and separated from the metallic coating of the said one member by an insulating layer, and an insulating layer formed on the other of the first and second members in locations to overlie the conductive tracks.

2 A waveguide assembly as claimed in Claim 1, wherein the first and second members are moulded plastics members.

3 A waveguide assembly as claimed in either preceding claim, wherein the first and second members are injection moulded.

4 A waveguide assembly as claimed in any one of Claims 1 to 3 , wherein the first and second members are vacuum formed. 5 A waveguide assembly as claimed in any preceding claim, wherein the metallic coating is formed by electroless copper plating.

6 A waveguide assembly as claimed in Claim 5, wherein the electroless copper plating provides a continuous copper layer.

7 A waveguide assembly as claimed in Claim 6, wherein the copper layer is between 2.5 and 3.5 microns thick.

8 A waveguide assembly as claimed in any preceding claim, wherein he insulating layers and metallic tracks are in the region of 0.1 microns thick.

9 A phased array for microwave radiation, comprising a waveguide assembly as claimed in any preceding claim, and a plurality of phase shifting components disposed with the waveguide channels at predetermined locations, said conductive tracks extending into said waveguide channels at said predetermined locations for connecting a bias voltage to the phase shifting components.