GB2054974A - Tracking Mode Couplers for Use in Radar and Communications Tracking Systems - Google Patents
Tracking Mode Couplers for Use in Radar and Communications Tracking Systems Download PDFInfo
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- GB2054974A GB2054974A GB8016107A GB8016107A GB2054974A GB 2054974 A GB2054974 A GB 2054974A GB 8016107 A GB8016107 A GB 8016107A GB 8016107 A GB8016107 A GB 8016107A GB 2054974 A GB2054974 A GB 2054974A
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- 230000008878 coupling Effects 0.000 claims abstract description 36
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- 238000005859 coupling reaction Methods 0.000 claims abstract description 36
- 230000004044 response Effects 0.000 claims description 3
- 230000001902 propagating effect Effects 0.000 claims 2
- 230000000644 propagated effect Effects 0.000 abstract description 16
- 238000000605 extraction Methods 0.000 abstract description 4
- 230000007717 exclusion Effects 0.000 abstract description 3
- 230000005284 excitation Effects 0.000 description 8
- 238000012937 correction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
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- 230000000694 effects Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 101100314154 Arabidopsis thaliana TOE2 gene Proteins 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/16—Auxiliary devices for mode selection, e.g. mode suppression or mode promotion; for mode conversion
- H01P1/161—Auxiliary devices for mode selection, e.g. mode suppression or mode promotion; for mode conversion sustaining two independent orthogonal modes, e.g. orthomode transducer
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/16—Auxiliary devices for mode selection, e.g. mode suppression or mode promotion; for mode conversion
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Abstract
The invention provides a tracking mode coupler capable of substantially complete extraction of tracking mode signal energy, to the exclusion of all unwanted modes, for use in either a radar or a communications tracking system. In essence the coupler comprises a primary waveguide 1 which will propagate a dominant mode and at least one higher order tracking mode from a received off-axis signal at the operating frequency, and an oversized secondary waveguide 3 which is coupled to the primary waveguide 1, preferably by means of two separate coupling apertures 6 and 7, in such a way that the tracking mode or modes in the primary waveguide propagate the dominant mode in the secondary waveguide, and the dominant mode in the primary waveguide propagates a higher order mode in the secondary waveguide. In addition, the primary waveguide 1 has a mode selective filter 9, preferably a reflecting filter, for allowing only the dominant mode in the primary waveguide 1 to pass, and the secondary waveguide 3 has a similar mode selective filter 8 for allowing only the dominant mode in the secondary waveguide to pass. Consequently the output from the secondary waveguide 3 is derived solely from the higher order tracking mode or modes propagated in the primary waveguide 1. <IMAGE>
Description
SPECIFICATION
Tracking Mode Couplers for Use in Radar and Communications Tracking Systems
In radar and communication systems in which a reflector antenna receives signals from a target,
i.e. a reflecting object in the case of a tracking radar system or a beacon emitter, such as a sateilite, in a
communications system, it is essential for efficient operation of the system that the target and the axis
of the reflector antenna are maintained in alignment with each other. Even small deviations from the
correct alignment lead to a marked decrease in signal strength and purity. Consequently, such systems
are provided with an automatic tracking system which is designed to detect any error in alignment
between the target and the antenna axis and to correct the antenna direction accordingly.
This invention relates to such tracking systems in which the alignment error is detected using a
waveguide which is connected to the feed horn of the antenna and which is designed to propagate only
the fundamental or dominant mode which is generated by the horn at the operating frequency or
frequencies when the antenna is correctly aligned (i.e. no error) but will propagate at least one higher
order mode in addition to the dominant mode when the antenna is off boresight, i.e. misaligned, the
higher order mode or modes being extracted from the waveguide and fed to a tracking receiver which
determines the error and operates the antenna correction mechanism.The higher order mode or modes
which are used for the tracking operation are extracted from the waveguide by means of secondary
waveguides which are suitably coupled to the primary waveguide, and the whole assembly is called a
tracking mode coupler.
In one known form of tracking system, which achieves target/beacon tracking in 0/sfi angular
coordinates, the tracking coupler comprises a circular primary wave-guide which propagates the
dominant TE1 mode at the operating frequency or frequencies, and for tracking purposes the higher
order TMo1 mode is used. Two or more secondary waveguides are coupled symmetrically to the
circular primary guide for the extraction of the tracking mode signal energy, and using magic T's the
sum total of this energy is obtained and compared in the tracking receiver with a reference channel
(sum) TE11 mode at the target/beacon frequency to give an indication of the angular deviation. The
reference sum signal is generally filtered from the radar or communications signal receiving circuit.
Systems based on this approach suffer from requiring high accuracy phase sensitive receivers, and
sometimes also from being limited to use with circularly polarised signals.
In a similar system which is not so limited, the circular primary waveguide is designed to
propagate two higher order modes, the Two1 and TE21 modes, for tracking purposes, and there are two
axially separated pairs of rectangular secondary waveguides for extracting these tracking modes. One
pair of the secondary waveguides is designed to accept only the TE21 tracking mode, and the other pair
of secondary waveguides is designed to accept only the TMo1 tracking mode. The extracted TMo1 derived
signals are summed and the extracted TE2, derived signals are subtracted using magic T's, and the sum and difference signals obtained are further summed and subtracted using a third magic T to
provide the antenna correction signals.A major disadvantage of this tracking coupler is its excessive
length and bulk, and the size of the tracking receiver which involves three separate magic T's.
In another form of tracking coupler which has recently been developed for a cartesian (x,y)) tracking system for a communications satellite, the higher order TMo1 and TE201 modes propagated in
response to off-axis signals in a circular primary waveguide are again used as the tracking modes.
However, the overall length of the primary waveguide is much less than in the previous system, since the tracking modes are extracted by two pairs of opposed rectangular secondary waveguides
positioned at right angles to each other and in the same plane. The signal energy extracted at the
beacon frequency by each of the secondary waveguides includes contributions from each tracking
mode and also from the dominant TE11 mode of the primary waveguide, and these contributions are
isolated and processed in a tracking receiver involving four magic T's to provide sum signals (x and ỳ obtained from the
contributions) and difference signals (Ax and by obtained by subtracting and summing the isolated TMo 1 and To201 contributions) for processing in a four channel receiver to produce a normalised error signal. However, while the actual mode coupler is fairly compact and the method of abstraction has the advantage that the system is insensitive to the effects of signal depolarisation, the tracking receiver is particularly bulky due to the requirement four magic T's.Also this system is only really suited to communications systems in which a discrete beacon signal operates at a frequency which is different to that of the carrier frequency bands.
The aim of the present invention is to provide a simple and compact form of tracking mode coupler which can be used in various types of radar and communications tracking systems, and which permits the tracking receiver necessary to process the tracking mode signals extracted and provided by the coupler also to be relatively simple and compact, particularly in the case of angular and cartesian co-ordinate tracking systems.
To this end, according to the invention a tracking mode coupler comprises a primary waveguide which is designed to propagate only a dominant mode from an axially aligned signal received at a given operating frequency and to propagate the dominant mode together with a higher order mode (tracking mode) from an off-axis signal at the operating frequency, and an oversized secondary waveguide which is coupled to the periphery of the primary waveguide in such a way that the tracking mode and the dominant mode in the primary waveguide respectively propagate a dominant mode and a higher order mode in the secondary waveguide, the primary waveguide having a mode selective filter downstream from the secondary waveguide, in the receive direction, for allowing only the dominant mode in the primary waveguide to pass, and the secondary waveguide having a mode selective filter remote from the primary waveguide for allowing only the dominant mode in the secondary waveguide to pass.
The dominant mode which is allowed to exit from the secondary waveguide of the coupler is derived from the higher order tracking mode propagated in the primary waveguide, and since only the dominant mode in the secondary waveguide is allowed to exit from this guide, the coupler in accordance with the invention derives a pure tracking signal for supply to the tracking receiver. In other words, the coupler in accordance with the invention selectively extracts the tracking mode from the modes propagated in the primary waveguide of the coupler for supply directly as a pure tracking signal to the tracking receiver, making it unnecessary to provide the receiver with means for isolating the tracking signal from other extracted signal components.
The tracking coupler will normally be located between the horn and the polariser of the antenna feed, and will be designed so that the tracking mode is extracted from the primary waveguide as efficiently as possible (preferably O dB), bearing in mind that in the case of a radar system this must be effected at the radar operating frequency and in the presence of the high and low power transmitted and received signals respectively. For this purpose, the coupling between the primary and secondary waveguides comprises at least two separate coupling apertures whereby double feeding of the secondary waveguide is provided and a high mode purity in the primary waveguide is maintained. In addition, the mode selective filters in the primary and secondary waveguides are preferably high-pass reflecting filters formed by a suitable tapering of the waveguides.The shape and length of the waveguide tapers are determined in accordance with known principles to achieve low transmission loss and good VSWR characteristics for the dominant mode signals (i.e. the radar or beacon signals) in the primary waveguide.
The coupling apertures feeding into the secondary waveguide are preferably located on opposite sides of the primary waveguide, and the primary waveguide is arranged to centre excite the secondary waveguide. The apertures, which are preferably rectangular, may be arranged longitudinally or transversely with respect to the axis of the primary waveguide depending on the tracking mode or modes to be extracted and the cross-sectional shape of the waveguide. The primary waveguide may be rectangular (including square) or circular in cross-section. Similarly, the secondary waveguide may be rectangular or circular in cross-section, although it will be usual for the secondary waveguide to be rectangular.
The invention can of course also be applied to tracking couplers in which many different modes are propagated in the primary waveguide in response to off-axis signals received by the antenna horn, the coupler being designed to extract one or more of the higher order modes as tracking modes as desired. In this case it is only essential to ensure that the higher order mode or modes which it is desired to use for tracking purposes are coupled to the secondary waveguide as the dominant mode in the secondary waveguide, and that the dominant mode and any other mode which is not wanted for tracking is coupled to the secondary waveguide as a higher order mode or is not coupled at all. Also, the tracking coupler may have more than one secondary waveguide arranged to operate on the same principle as each other to extract and output higher order tracking modes to the exclusion of unwanted modes.In this case it may be necessary to provide the tracking receiver with means for isolating one tracking mode from another.
Various examples of tracking mode couplers in accordance with the present invention will now be described with reference to the accompanying drawings, in which:
Figure 1 is a diagrammatic, partially cut-away perspective view of a first example which is suitable for use in a single plane tracking system in either a radar or a communications system;
Figures 1 a and 1 b are diagrams of the coupling apertures between the primary and secondary waveguides of the tracking coupler of Figure 1 illustrating the excitations of the apertures which are produced by the surface currents flowing on the walls of the primary waveguide as a result of the
modes propagated therein and which are responsible for mode propagation in the secondary
waveguide; ;
Figures 2, 3 and 4 are similar views to that of Figure 1, but illustrating diagrammatically three more examples of a tracking coupler in accordance with the invention for use in single plane tracking systems;
Figure 5 is a view similar to that of Figure 1, but illustrating an example of a tracking coupler in
accordance with the invention suitable for use in an angle (0/0) tracking system in either a radar or a
communications system;
Figure 5a is a diagrammatic vertical section on the line V-V in Figure 5 illustrating more clearly the location of the coupling apertures between the primary and secondary waveguides of the coupler;;
Figure 5b is a view similar to that of Figure 5a but showing an alternative form of the tracking coupler in which the coupling apertures are located in different positions;
Figure Sc is a diagram of the surface currents generated on the walls of the primary waveguide of the coupler of Figures 5 and 5a by the modes propagated therein, and illustrating the excitation of the coupling apertures by the currents;
Figure 6 is a view similar to that of Figure 5, but illustrating an example of a tracking coupler in accordance with the invention suitable for use in a cartesian (x/y) tracking system for either a radar or a communications system; and,
Figure 7 is a diagram illustrating the operation of the tracking receiver required to process the tracking outputs from the coupler shown in Figure 6.
In the example shown in Figure 1, the primary waveguide of the tracking coupler is a rectangular waveguide 1 dimensioned to promote propagation of the dominant TElo mode for both transmitted and
received (target reflection) radar or communications signals, together with an incoming higher order TE200 mode when the received signal is off-axis, this being the higher order waveguide mode selected to derive the tracking information.
Mounted on one of the wider faces 2 of the primary waveguide 1 is a secondary rectangular waveguide 3, having its axis 4 perpendicular to the axis 5 of the primary guide. In the coupling plane between the primary and secondary waveguides the primary guide 1 is provided with a pair of rectangular coupling apertures 6 and 7 which feed into the secondary guide 3 and which are arranged longitudinally with respect to the primary guide axis 5 and near the edges of the primary guide face 2.
Provided the secondary waveguide 3 is oversized in the coupling plane, the excitation of the coupling apertures 6 and 7 by the dominant TE,o and the higher order TE20 modes in the primary waveguide will propagate TE11 (higher order) and TE,o (dominant) modes respectively in the secondary waveguide 3.
The excitations of the coupling apertures are illustrated by the arrows across the apertures in Figures 1 a and 1 b, and the mode conversions are summarised in the following table.
As will be noted, the dominant TE1ao mode in the secondary waveguide 3 is derived solely from the higher order TE22o tracking mode in the primary guide 1, and is extracted from the coupler as a pure tracking signal by providing the secondary waveguide 3 with a tapered portion 8 which forms a high pass reflecting filter which passes the derived TE,Oa tracking signal but reflects the higher order derived TE,n,mode. This reflected mode is reconverted by the coupling apertures 6 and 7 to the dominant TE 0
10 mode in the primary waveguide 1 so that there is virtually no loss of signal energy in the coupler.
Similarly, the primary waveguide 1 is tapered downstream (in the direction of the received signals from the secondary waveguide 3 to form a mode selective filter 9 which passes only the dominant TE 0
10 mode and reflects the TE20a tracking mode to ensure that substantially all the tracking mode energy is coupled to and extracted by the secondary waveguide 3.
In the example illustrated in Figure 2, the primary and secondary waveguides of the coupler are again both rectangular guides and are indicated at 10 and 11 respectively. In this case the secondary guide 11 brackets the primary guide 10 so that it is arranged to be centre excited by means of a pair of rectangular coupling apertures 12 and 1 3 which are arranged longitudinally with respect to the longitudinal axis 14 of the primary waveguide 10 in opposite walls 1 5 and 1 6 of the guide.In this case both the primary and secondary waveguides 10 and 11 are dimensioned to be multimoded at the operating frequency, and the modes which are propagated in the secondary waveguide 11 as a result of excitation of the coupling apertures 1 2, 1 3 by the modes propagated in the primary waveguide 10 are listed in the following table::
In this case the higher order modes propagated in the primary waveguide 10 which will be used for tracking purposes are the TE2no and TE02 modes, both of which propagate the dominant TE,o mode in the secondary waveguide 1 There is little or no coupling of the dominant TEano mode in the primary waveguide 10, but the TEo1 mode couples to the higher order TE" mode in the secondary guide 11. As in the first example, both the primary and secondary guides 10 and 11 will include suitable high pass reflecting filters which will be designed to pass only the dominant modes in the respective waveguide and to reflect the higher order modes.These mode selective filters of the primary and secondary waveguides 10 and 11 are not illustrated in Figure 2, nor in Figures 3 and 4 although the tracking couplers illustrated therein will of course include such filters.
In the example illustrated in Figure 3 the coupler is very similar to that shown in Figure 2, except that the coupling apertures 1 7, 1 8 which are located in the opposite faces 1 9, 20 respectively of the primary waveguide 21 and which centre excite the secondary waveguide 22, are arranged transversely with respect to the longitudinal axis 23 of the primary guide 21.The modes which are propagated in the primary and secondary waveguides of this example are listed in the following table:
In this case it is the higher order
mode combination which converts to the dominant TE1no mode in the secondary waveguide 22 and which is used to derive the required tracking signal.
Another similar centre excited tracking coupler is shown in Figure 4. In this case the coupling apertures 24, 25 are again located transversely to the longitudinal axis 26 of the primary waveguide 27, but are offset towards diagonally opposite edges of the primary guide 27. In this case the modes which propagate in the primary and secondary waveguides 27 and 28 are given in the following table, from which it will be seen that it is the higher order TE2no and
modes in the primary waveguide 27 which propagate the dominant TE1no mode in the secondary guide 28 and which will be used for tracking purposes.
An example of a tracking coupler in accordance with the invention and suitable for use in an angular co-ordinate (H/0) tracking system is illustrated in Figure 5. In this case the coupler comprises a primary waveguide 29 which has a circular cross-section and is designed to propagate both the dominant TE" modes together with the higher order TMO, mode (for tracking purposes) generated by off-axis signals received by the feed horn of the antenna. Towards one end of the primary waveguide 29 (remote from the end which in use is connected to the feed horn) the guide 29 is provided with a tapered section 30 which forms a mode reflection filter to reflect the incoming higher order tracking mode signal energy while allowing efficient passage of the dominant mode signal energy at both the transmit and receive frequencies.
The secondary waveguide of the coupler shown in Figure 5 is a rectangular waveguide 31 which is coupled to the primary guide 29'so that it is centre excited by means of two diametrically opposite rectangular coupling apertures 32, 33 which are arranged transversely with respect to the longitudinal axis 34 of the primary guide 29. The secondary waveguide 31 is over sized in the coupling region so that it is able to propagate the higher order TE2 mode in addition to the dominant TE,o mode, although further away from the coupling region the secondary waveguide 31 is provided with a tapered portion 35 forming a mode reflecting filter which allows only the dominant TE,o mode to pass. The location of the coupling apertures 32, 33 in relation to the secondary guide 31 is shown more ciearly in Figure 5a.
The dimension A represents the oversize nature of the secondary guide 31 and in the present example is selected to prevent propagation of the higher order TE300 mode.
Figure Sc illustrates the excitations of the two coupling apertures 32, 33 by the surface currents 36, 37, 38 flowing in the wall of the primary waveguide 29 as a result of the two dominant TE" modes and the higher order TMoa mode propagated in the primary guide 29, the wall of the guide being shown flat for the sake of convenience.The modes which are propagated in the secondary guide 31 as a result of the coupling aperture excitations are summarised in the following table:
As will be noted, the dominant primary guide
mode propagates the higher order TE2 o mode which is rejected by the mode reflecting filter 35 in the
secondary guide 31, whereas the TMo1 tracking mode in the primary guide 29 propagates the
dominant TE,o mode in the secondary guide 31.By virtue of a direct coupling of the tracking mode to
the secondary waveguide 31, combined with the coupling of the portion of the tracking mode energy
which initially passes the coupling plane but which is reflected back by the mode reflecting filter 30 of
the primary guide 29, substantially complete extraction (0 dbcoupling) of the tracking mode energy is
possible. Consequently, the derived TE1 o mode which exits from the secondary waveguide 31 is a pure
tracking signal for use by the tracking receiver of the radar or communications system, in conjunction
with a reference channel (sum) signal filtered from the receiving circuit of the system to compute the
required tracking correction.
Figure 5b shows a modified form of the tracking coupler of Figure 5 in which the coupling
apertures 32b, 33b between the primary and secondary waveguides 29b and 31 b are positioned so
that their centres subtend a 900 angle at the axis 34b of the primary guide 29b, the angle being
bisected by the axis 39 of the secondary guide 31 b.
(Figure 6 illustrates an example of the tracking coupler in accordance with the invention suitable
for use in cartesian (x/y) tracking system. The coupler is similar to that shown in Figure 5 except that the circular primary waveguide 40 is designed to propagate an additional higher order mode, i.e. the TOE2, mode, for tracking purposes, and in that there are two rectangular secondary waveguides 41 and
42 for extracting the tracking mode energy, each secondary guide being coupled to the primary guide
40 so that it is centre excited by a pair of diametrically opposite rectangular coupling apertures 43, 44
and 45, 46 located in the wall of the primary guide 40 transverse to the longitudinal axis 47 of the
primary guide.The two secondary waveguides 41, 42 are offset from each other with respect to the
axis 47 of the primary guide 40 and extend at right angles to the said axis 47 and to each other.
The waveguide modes propagated in the secondary waveguides 41, 42 as a result of excitation
of the coupling apertures 43 to 46 by the modes propagated in the primary guide 40 from off-axis
signals received by the antenna horn at the radar/beacon frequency are indicated in the following two
tables, the first table corresponding to the secondary guide 41 excited by the slots numbered 43 and
44, and the second table corresponding to the secondary guide 42 excited by the slots 45 and 46.
From these tables it will be seen that the dominant TE" modes in the primary guide 4Q propagate higher order TE2z0 modes in the secondary waveguides 41, 42, these being reflected by the mode reflecting filters 48, 49 of the secondary guides and reconverted to the TE, , mode in the primary guide 40. In addition, it will be seen that both the TMo 1 and the
tracking modes, which cannot pass the mode reflecting filter 50 of the primary guide 40, convert to thedominant TE10 mode in the secondary waveguides 41, 42.However, because of the orthogonal arrangement of the two secondary waveguides 41, 42 the components of the TE1ao output from the secondary guides derived from the TE2 1 tracking mode will be of opposite phase, but provided that the tracking modes propagated in the primary guide 40 are of equal phase and amplitude, the outputs from the secondary waveguides 41, 42 can be summed and subtracted by a magic T in the tracking receiver of the radar or communications system to isolate the two tracking mode components. The isolated components are then summed and subtracted by a further magic T to give Ax and Ay error signals.
This function of the tracking receiver is illustrated diagramatically in Figure 7. In this case only two magic T's 51 and 52 are required compared with the four magic T's required to obtain the Ax and by signals in the recently proposed system described earlier. The sum (x and ỳ) signals required to produce normalised error signals from the Ax and hy information may be extracted by filtering in the communications/radar receiver circuit.
In summary, a tracking mode coupler in accordance with the invention offers a neat and compact solution to the problem of extracting tracking mode signal energy for use in a convenient manner in either a radar or a communications system. In fact, the coupler is effectively mode selective in that it enables substantially complete extraction of the required tracking mode or modes, to the exclusion of all unwanted modes at the operating frequency, with little or no effect on the transmitted and received communications or radar signals which the coupler has to pass.
Claims (11)
1. A tracking mode coupler for use in a radar or communications tracking system, the coupler comprising a primary waveguide which is designed to propagate only a dominant mode from an axially aligned signal received at a given operating frequency and to propagate the dominant mode together with a higher order tracking mode from an off-axis signal at the operating frequency, and an oversized secondary waveguide which is coupled to the periphery of the primary waveguide in such a way that the tracking mode and the dominant mode in the primary waveguide respectively propagate a dominant mode and a higher order mode in the secondary waveguide, the primary waveguide having a mode selective filter downstream from the secondary waveguide, in the receive direction, for allowing only the dominant mode in the primary waveguide to pass, and the secondary waveguide having a mode selective filter remote from the primary waveguide for allowing only the dominant mode in the secondary waveguide to pass.
2. A tracking mode coupler according to claim 1, in which the coupling between the primary and secondary waveguides comprises at least two separate coupling apertures for double feeding the secondary waveguide.
3. A tracking mode coupler according to claim 2, in which the coupling apertures are located on opposite sides of the primary waveguide, and the primary waveguide is arranged to centre excite the secondary waveguide.
4. A tracking mode coupler according to claim 2 or claim 3, in which the coupling apertures are rectangular and are arranged longitudinally with respect to the axis of the primary waveguide.
5. A tracking mode coupler according to claim 2 or claim 3, in which the coupling apertures are rectangular and are arranged transversely with respect to the axis of the primary waveguide.
6. A tracking mode coupler according to any one of the preceding claims, in which the mode selective filters of the primary and secondary waveguides are high pass reflecting filters formed by suitably tapered sections in the waveguides.
7. A tracking mode coupler according to any one of the preceding claims, in which the primary and secondary waveguides are each rectangular in cross-section.
8. A tracking mode coupler according to any one of claims 1 to 6, in which the primary and secondary waveguides are respectively circular and rectangular in cross-section.
9. A tracking mode coupler according to any one of the preceding claims, in which the primary waveguide is designed to propagate more than one higher order mode for tracking purposes in response to off-axis signals at the operating frequency, each tracking mode propagating the dominant mode in the secondary waveguide, and the dominant mode and any other higher order mode in the primary waveguide which is not wanted for tracking purposes propagating in the secondary waveguide either a higher order mode or no mode at all.
10. A tracking mode coupler according to any one of the preceding claims, in which there is more than one secondary waveguide coupled to the primary waveguide in such a way as to extract and output the higher order tracking mode or modes from the primary waveguide as the dominant mode in the secondary waveguides.
11. A tracking mode coupler according to claim 1, substantially as described with reference to any one of Figures 1 to 6 or to Figure 5 modified as in Figure Sb of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8016107A GB2054974B (en) | 1979-05-15 | 1980-05-15 | Tracking mode couplers for use in radar and communications tracking systems |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7916864 | 1979-05-15 | ||
| GB8016107A GB2054974B (en) | 1979-05-15 | 1980-05-15 | Tracking mode couplers for use in radar and communications tracking systems |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2054974A true GB2054974A (en) | 1981-02-18 |
| GB2054974B GB2054974B (en) | 1983-02-02 |
Family
ID=26271531
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8016107A Expired GB2054974B (en) | 1979-05-15 | 1980-05-15 | Tracking mode couplers for use in radar and communications tracking systems |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2054974B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0096461A2 (en) * | 1982-06-04 | 1983-12-21 | Andrew A.G. | Microwave systems |
| EP0116418A2 (en) * | 1983-01-28 | 1984-08-22 | Andrew A.G. | Multi-port, multi-frequency microwave combiner |
| EP3910729A1 (en) * | 2020-05-15 | 2021-11-17 | Thales | Broadband orthomode transducer |
-
1980
- 1980-05-15 GB GB8016107A patent/GB2054974B/en not_active Expired
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0096461A2 (en) * | 1982-06-04 | 1983-12-21 | Andrew A.G. | Microwave systems |
| EP0096461A3 (en) * | 1982-06-04 | 1986-03-12 | Andrew Corporation | Microwave systems |
| EP0116418A2 (en) * | 1983-01-28 | 1984-08-22 | Andrew A.G. | Multi-port, multi-frequency microwave combiner |
| EP0116418A3 (en) * | 1983-01-28 | 1986-03-19 | Andrew Corporation | Multi-port, multi-frequency microwave combiner |
| EP3910729A1 (en) * | 2020-05-15 | 2021-11-17 | Thales | Broadband orthomode transducer |
| FR3110290A1 (en) * | 2020-05-15 | 2021-11-19 | Thales | Wideband orthomode transducer |
| US11476553B2 (en) | 2020-05-15 | 2022-10-18 | Thales | Wideband orthomode transducer |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2054974B (en) | 1983-02-02 |
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| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |