GB2140977A - Waveguide coupling - Google Patents

Description

1 GB 2 140 977 A 1

SPECIFICATION

Waveguide connection arrangement The present invention relates to the connection and disconnection of waveguides and is particularly concerned with microwave interfaces on items of equipment which need to be rapidly connected and disconnected, such as radar and other military equipment.

Hitherto, detachable waveguide connections have been made by bolting together flanged mating surfaces of the waveguides. This procedure which generally involves the tightening or untightening of a number of nuts and bolts, it time consuming and awkward, particularly when the connection is not easily accessible. However, it has hitherto been believed that a tight bolted flange connection is necessary in order to ensure low power losses at the mating interface and to ensure that dirt and moisture 85 are excluded.

We have found that a satisfactory connection with sufficiently low losses can be achieved without using a tightly locked mating interface.

According to the present invention a two-part sliclably detachable waveguide connector is provided on one part with a slidable first waveguide portion sliclable in the axial direction and biassed away from said part by spring means; on the other part with a second waveguide portion arranged to mate with said first waveguide portion and on either part with a tubular outer sleeve which sliclably locates said wave-guide portions and surrounds their mating interface when the connector parts are attached.

Said connector may be incorporated in an arrangement further comprising guide means distinct from said connector which in use sliclably located the connector parts and align them when they are separated. Thus one of the waveguide connector parts may be mounted on the rear of the casing on a piece of equipment arranged to be rack-mounted and the other waveguide connector part is then mounted at a corresponding position on the rack, so that the connector parts can be mated simply by sliding the equipment into the rack and held in position by frictional engagement between the equipment and the rack. Any slight initial mismatch in the positions or orientations of the connector parts may be accommodated by providing an alignment taper on the engaging surfaces of either or both of the connector parts. However the waveguide portions should be a close sliding fit in the outer sleeve in order to ensure their mating faces accurately abut one another, and thereby ensure low 120 electrical losses at the interface. Normally any strain on the connector caused by slight initial misalignment will be taken by the flexible casing of the equipment, or the rack.

The invention is however also applicable to multi- 125 ple bayonet connectors as used in military applications, for example.

Preferably the outwardly biassed waveguide portion is mounted on one (male) part of the connector and the tubular guide is incorporated in the other (female) part of the connector. The connector may incorporate a shutter over the recessed mating surface of the female part of the connector which is opened by a coarse alignment pin on the male connector part when the parts are brought together.

One of the mating surfaces (which are preferably planar) may be provided with a groove surrounding the inner surface of the waveguide. The groove acts as a waveguide choke at the connector interface and thereby reduces the mismatch in impedance between the connector parts (which is inherent in all waveguide and transmission line discontinuities) and hence any power losses which might otherwise occur.

In most cases the lengths of waveguide connected by the connector will be rectangular in cross section and will need to be rotationally aligned about their common axis. One length of waveguide may be gripped within the tubular guide and the tubular outer sleeve(which may suitably by circular in cross-section) in turn may be aligned by means of a pin mounted of the body of the associated connector part which engages an axial slot in its surface. The bodies of the connector parts may be relatively aligned by means of a dowel pin projecting from one body into a hole in the other.

Embodiments of the invention will now be described by way of example with reference to Figures 1 to 7 of the accompanying drawings, of which:

Figure 1 is an axial sectional elevation of one part of a connectorfor use in an arrangement in accordance with the invention; Figure 2 is a plan view taken on Figure 1; Figure 3 is an axial sectional elevation of another connector part suitable for fitting to that shown in Figures 1 and 2; Figure 4 is a plan viewtaken on Figure 3; Figure 5 is a sectional elevation showing the connector parts of Figures 1 to 4 in a schematic arrangement in accordance with the invention, and Figure 6a is an axial section of one part of a bayonet connector for use in an arrangement in accordance with the invention, Figure 6b is an axial section of a corresponding connector part aligned with the connector part of Figure 6a, and Figure 7 is an axial section showing the connector parts of Figures 6a and 6b locked together. Similar parts are indicated by corresponding reference num- berals throughout the drawings.

Referring first to Figures 1 and 2, the connector part shown comprises a guide tube 1 integral with a supporting flange 2 and a tubular insert member 3 which is a sliding fit in the guide tube. A rectangular section waveguide 4 is brazed to the inner wall of insert member 3 so as to lie flush with a flat mating surface 9 of the latter. Supporting flange 2 is provided with four holes 5 and tubular insert member 3 is similarly provided with fourthreaded holes 6 (Figure 2) on its flange portion so that the supporting flange 2 and tubular insert member 3 can be bolted to a common supporting plate (not shown) which is thus clamped between them. Guide tube 1 is provided with a tapered alignment surface 7 to enable the corresponding male part of the connector GB 2 140 977 A 2 (shown in Figures 3 and 4) to be inserted into guide tube 1.

The corresponding male part of the connector comprises a tubular waveguide portion 10 (Figure 3) provided with a flat mating surface 11. A section of waveguide 12 is brazed to the inside wall of wave guide portion 10 and lies flush with surface 11. A tapered alignment surface 13 is provided on the perimeter of surface 11, enabling waveguide portion 10 to be slid into the guide portion 1 of the female connector part shown in Figures 1 and 2. Waveguide portion 10 is slidingly supported by a supporting flange 14 and biassed outwardly by a spring 15 which acts on a ring 16 which is in turn held in place by a clip 17. Outward movement of waveguide 80 portion 10 is limited by an annular stop 18, and a pin 19 projects into an axial slot 20 to ensure rotational alignment of waveguide portion 10 with flange 14.

Figure 5 shows an arrangement incorporating the connector parts of Figures 1, 2 and 3, 4 mounted on the rear of an equipment casing 21 and a vertical member 22 of a rack respectively. Shelves 23 and 24 of the rack co-operate with the casing 21 to guide the two parts of the connector into mating engagement as shown when the equipment is slid into the rack as indicated by arrow A, the extent of this travel being limited by one or more stops 25. Spring 15 acts against frictional engagement between casing 21 and shelf 23 to force mating surfaces 11 and 9 into close contact. Waveguide section 12 need not be particularly flexible but it shoulf be long enough to allow reasonable freedom of movement of wave guide portion 10 in the direction of arrow A. The connection may be broken simply by withdrawing the equipment from the rack inthe opposite direction 100 to arrow A. It will be apparent that the invention includes within its scope similar arrangements in which mating surface 9 rather than mating surface 11 is outwardly spring biassed or in which guide tube 1 is integral with waveguide portion 10 and co-operates with a male connector part mounted on the equipment casing.

Figure 6a shows a connector part comprising a waveguide portion 10 slidably mounted within a guide tube 1. A rectangular section of waveguide 12 is fitted into waveguide portion 10 and is rotationally aligned by a pin 19 which engages a longitudinal slot 20. A guide bushing 25 mounted via a carrier member 26 on guide tube 1 is a sliding fit around waveguide portion 10. A rotatable locking collar 27 is slidably mounted on a carrier 26 and is spring biassed away from the direction of engagement by means not shown. Waveguide portion 10 is provided with a flat mating surface 9 and is biassed outwardly by a spring 15.

The corresponding connector part shown in Figure 6b is fixed to an equipment casing 21 (by means not shown) and comprises a tube 28 within which is mounted a waveguide portion 1 Wfrom a flange 29.

A rectangular waveguide section 12' runs to wave guide portion 1 Wfrom the interior of the equipment casing. Dowel pins 30 ensure rotational alignment of the waveguide portion 10 with tube 28.

The locking collar 27 is provided with a bayonet slot 31 and tube 28 is provided with a corresponding locking portion 32. The connector parts may be interlocked as shown in Figure 7 by rotating collar 27 to align locking portion 28 with its bayonet slot 31 and then further rotating collar 27 to prevent with- drawal. The connector parts are rotationally aligned relative to each other by longitudinal ribs (not shown) in carrier member 26 which engage in corresponding slots (not shown) in the inside surface of tube 28.

Claims (11)

1. Atwo-part slidably detachable waveguide connector, wherein a firstwaveguide portion slidable in the axial direction is carried by one part and biassed away from said part by spring means, a second waveguide portion arranged to mate with said first waveguide portion is carried by the other part and a tubular outer sleeve is carried by either part and, when the connector parts are attached, slidably locates said waveguide portions and surrounds their mating interface.

2. Awaveguide connector as claimed in Claim 1 wherein said outwardly biassed waveguide portion is mounted on a male connector part and thrtubular outer sleeve is incorporated in a mating female connector part.

3. A waveguide connector as claimed in Claim 2 wherein a shutter is provided over the recessed mating surface of the female part of the connector, which shutter is opened by a coarse alignment pin on the male connector part when the parts are brought together.

4. Awaveguide connector as claimed in any preceding claim wherein a groove surrounding the inner surface of the waveguide is provided on one of the mating surfaces of the connector.

5. Awaveguide connector according to any preceding claim wherein the bodies of the connector parts are relatively aligned by means of one or more dowel pins projecting from one body into a hole in the other.

6. A multiple bayonet connector incorporating a waveguide connector as claimed in any preceding claim.

7. An arrangement comprising a waveguide connector as claimed in any of Claims 1 to 5, said arrangement further comprising guide means distinct from said connector which in use slidably locate the connector parts and align them when said parts are separated.

8. An arrangement according to Claim 7 wherein a rack constitutes said guide means and one of said waveguide connector parts is mounted on the rear of the casing of a rack-mountable piece of equipment and the other of said waveguide connector parts is mounted at a corresponding position on the rack, so that the connector parts can be mated by sliding the equipment into the rack and held in position by frictional engagement between said piece of equipment and said rack.

9. Atwo-part slidably detachable waveguide connector substantially as described hereinabove with reference to Figures 1 to 4 of the accompanying drawings.

W z v e 3 GB 2 140 977 A 3

10. A two part slidably detachable waveguide connector substantially as described herein above with reference to Figures 6 and 7 of the accompanying drawings.

11. An arrangement according to Claim 7 substantially as described hereinabove with reference to Figure 5 of the accompanying drawings.

lo Printed in the UK for HMSO, D8818935,10,184,7102. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.