Arrangement for Interconnection of Waveguide Structures and a Structure for a Waveguide Structure Interconnecting Arrangement
An arrangement for interconnecting waveguide structures or components including waveguide flange adapter elements with a surface of a conductive material with a periodic or quasi-periodic structure formed by a number of protruding elements that allows waves to pass across a gap between a surface around a waveguide opening to another waveguide opening in a desired direction or path, at least in an intended frequency band of operation, and to stop wave propagation in the gap in other directions. The arrangement includes devices for interconnecting with a waveguide flange or adapter element without requiring electrical contact and assuring that the gap is present between at least one first surface formed by periodically or quasi-periodically arranged protruding elements and a surface around a waveguide opening of the other waveguide flange, hence assuring that the first surface is not in direct mechanical contact with the other, opposite, interconnecting, waveguide flange.
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The present invention relates to an arrangement for interconnection of waveguide structures having the features of the first part of claim 1. The invention relates to arrangements for use in the high, or very high, frequency region, e.g. above 30 GHz, or even above 300 GHz, but also for frequencies below 30 GHz.
The invention also relates to a structure for an arrangement for interconnecting waveguide structures according to the first part of claim 36.
BACKGROUNDFor measuring and/or analysing microwave or millimetre circuits and devices of different kinds, e.g. from filters, amplifiers etc. to much more complex multifunction systems, but also for other purposes, waveguide structures need to be interconnected, and normally so called waveguide flanges are used as transitions. The requirements on a good conductive contact between waveguide flange surfaces are high. Unless the conductive contact is very good, currents will flow between the flanges, resulting in a leakage, mismatch and losses which will reduce the performance of the circuit, and produce incorrect results in the case of measurements and calibrations, particularly at high frequencies. In order to assure a good conductive, electrical, contact, waveguide flanges need to be tightly and evenly connected to each other, e.g. a waveguide flange has to be tightly and evenly connected to a device under test or to a calibration arrangement. In addition, an extremely good waveguide machining is required in order to assure a good alignment between waveguide flanges. These are difficult and time-consuming operations, in particular if several measurements need to be done, and may lead to incorrectly attached systems.
In E. Pucci, P.-S. Kildal, “Contactless Non-Leaking waveguide flange Realized by Bed of Nails for millimetre wave Applications”, 6th European Conference on Antennas and Propagation (EUCAP), pp. 3533-3536, Prague, March 2012, a waveguide flange which is realized by a bed of pins, and working between 190 and 320 GHz is proposed. This flange, with a pin structure or a textured surface does not require a conductive contact when connected to a standard waveguide, which facilitates fabrication and mounting. The screws need not be tightened very well and it is not needed to assure a good electrical contact as is the case with standard waveguide flanges. However, it is a disadvantage that it may still be a difficult and a time consuming operation to fasten the screws to connect the waveguide flange, even if the requirements as to tightening the screws are reduced, and similarly it is time consuming to loosen, remove, the screws at disconnection.
In S. Rahiminejad, E. Pucci, V. Vassilev, P.-S. Kildal, S. Haasl, P. Enoksson, “Polymer Gap adapter for contactless, Robust, and fast Measurements at 220-325 GHz”, Journal of Microelectromechanical Systems, Vol. 25, No. 1, February 2016, a double-sided pin-flange gap adapter is disclosed which is to be placed between two flanges to avoid leakage. It is a drawback that mechanical contact still is required, although no electrical contact is needed. The mechanical contact is assured by means of screws as in other known arrangements, and it is a drawback that, if the screws are tightened too much, the adapter easily may be destroyed, or it can result in pin marks in the sensitive flange surfaces, which then may be ruined.
Since, as also referred to above, particularly, but not exclusively, for high frequencies, e.g. from about 10 GHz, or particularly from 30 GHz up to about 1 THz, when connecting two waveguide flanges there is required a high quality of both mechanical and electrical, or at least mechanical, contact between them, in order to obtain a high quality, a repeatable and non-radiating interface, and a low loss interconnection, e.g. allowing a good calibration or a reliable measurement.
However, the flanges or adapters discussed above have shown not to be suitable for production and operation at e.g. 60 GHz, or from 50-75 GHz, which is a wide band. Actually, none of the designs are suitable for V-band flanges, which is a problem.
Further, in for example a typical calibration procedure the operator has to connect the flanges of calibration standards and ports of a VNA, Vector Network Analyzer, a plurality of times. This is a very time consuming, complicated and tedious task, due to all the screws needed to achieve a good contact between all joining flanges. It requires a stable and repeatable contact both mechanically and electrically, or at least mechanically, and therefore four screws should always used, but due to the time consuming and tedious work, sometimes for example only two of the required number of screws, e.g. four, required to ensure a good electrical contact, are actually tightened in practice. If the connection is not perfect, e.g. if there is a slight angular displacement or if there is not a perfect fit, there may be a leakage from the waveguide into free space, and also an increased reflection at the connection. A calibration procedure, as well as a measurement procedure, is based on all such connections being as perfect as possible.
Thus, although, through the solutions discussed above, the need for a conductive or electric contact between waveguide structures, or waveguide flanges, is removed, there is still a need for improvement as far as waveguide structure interconnecting arrangements are concerned. There is also a need for providing arrangements and structures appropriate for different and other frequency bands.
SUMMARYIt is therefore an object of the present invention to provide an arrangement for interconnection of waveguide structures through which one or more of the above-mentioned problems can be overcome.
It is particularly an object to provide an arrangement for interconnection of waveguide structures, which is easy to use and operate.
It is also an object to provide an arrangement for interconnection of waveguide structures which enables interconnection in a fast and reliable manner with a minimum of interconnecting, e.g. screwing and unscrewing, operations for joining/disconnecting waveguide flanges, and facilitating interconnection e.g. for analysis, calibration or measurement of microwave or millimetre wave circuits or devices.
It is a particular object to provide an arrangement for interconnection of waveguide structures which can be used for high frequencies, e.g. above 10 GHz, or particularly above 30 GHz, but also for lower frequencies without any risk of reduced performance, measurement errors or calibration errors due to misalignment or leakage between interconnected waveguide structures, e.g. waveguide flanges.
It is a particular object to provide an arrangement, and a structure respectively, appropriate for different, and additional, frequency band, most particularly also for the frequency band 50-75 GHz, e.g. for 60 GHz, and even more particularly for interconnection of V-band flanges.
Particularly it is an object to provide an arrangement for interconnection of waveguide structures which is easy and cheap to fabricate.
It is a general object to provide an arrangement through which interconnection as well as disconnection of waveguide structures is facilitated.
It is also an object to provide an interconnecting arrangement, and a surface structure, which is robust and suitable for manufacture for different frequency bands, or independently of which is the desired frequency band.
Another object is to provide a flexible solution that can be implemented for interconnection of waveguide structures for operation in different desired frequency bands.
A most particular object is to provide an arrangement for interconnection of waveguide structures which is suitable for being used for interconnections e.g. in measurement systems for high as well as for low frequencies, in connection with different standard waveguides dimensions (such as WR15, WR12, . . . WR3) and the corresponding standard waveguide flange dimensions, and for different and wide frequency bands.
A particular object is to provide an interconnection arrangement which can be used for interconnection of standard waveguide flanges.
A further particular object is to provide an interconnecting arrangement for connecting an analysing or measuring instrument to a waveguide calibration standard or a device under test in such a way that existing calibration standards can be used and such that connection/disconnection can be done in an easier and faster manner than before.
Therefore an interconnecting arrangement as initially referred to is provided which has the characterizing features of claim 1.
A structure for use in an interconnecting arrangement as initially referred to is also provided which has the characterizing features of claim 36.
Advantageous embodiments are given by the respective appended dependent claims.
The invention will in the following be further described in a non-limiting manner, and with reference to the accompanying drawings, in which:
The flange adapter element 100 is adapted to provide an interconnection between two waveguide structures or components, e.g. also antennas, filters, receivers etc., 10,20 with conventional smooth waveguide flanges (see
Between two respective, opposite, pairs of protruding wing or flange sections, two through recesses, here comprising waists, 103 are formed by flange adapter element side walls, perpendicular to the textured surface 15, and tapering towards a central region outside the textured surface 15 on respective sides thereof disposed outside the waveguide short walls 152. Between two respective, opposite, pairs of protruding wing or flange sections two through recesses 102 are formed by flange adapter side walls, which are perpendicular to the textured surface 15. The recesses 102 are here substantially U-shaped with a substantially straight section interconnecting the legs of the U:s and located outside the textured surface at locations extending substantially in parallel with the long sides of the waveguide opening 3. The waist shaped recesses 103 and the U-shaped recesses 102 are so shaped, and have such dimensions, as to allow an interconnecting element 12 (cf. e.g.
The flange adapter element 100 preferably comprises a solid part made of brass, Cu, Al or any other appropriate material with a good conductivity, a low resistivity and an appropriate density. It may for example be plated with e.g. Au or Ag in environments where further corrosion protection is needed. It should be clear that also other materials can be used, e.g. any appropriate alloy. It can also be fabricated from a suitable plastic/polymer compound and plated with e.g. Cu, Au or Ag.
The flange adapter element 100 in the shown embodiment comprises a flange element on a central portion of which a periodical or quasi-periodic structure, also denoted a texture, 15 is disposed around the opening of a standard rectangular waveguide 3. It should be clear that in alternative embodiments the flange adapter element may have any other appropriate shape, allowing it to be connected between e.g. two waveguide flanges, a waveguide flange and an antenna or another device, a waveguide flange of a calibrating arrangement, a DUT (Device Under Test) etc. It may in different embodiments be provided as a separate flange adapter element, in other embodiments it may be adapted to be fixedly connected to a waveguide flange (cf e.g.
The texture, i.e. the periodic or quasi-periodic structure, 15 may e.g. comprise a structure comprising a plurality of protruding elements, e.g. pins 151 having a square shaped cross-section, but the protruding elements can also have other cross-sectional shapes such as circular or rectangular, comprise a corrugated structure, e.g. comprising elliptically disposed grooves and ridges as shown in
Through providing a connection between a conductive smooth flange surface or plane of a waveguide 20 (see
The non-propagating or non-leaking characteristics between two surfaces of which one is provided with a periodic texture (structure), is known from P.-S. Kildal, E. Alfonso, A. Valero-Nogueira, E. Rajo-Iglesias, “Local metamaterial-based waveguides in gaps between parallel metal plates”, IEEE Antennas and Wireless Propagation letters (AWPL), Volume 8, pp. 84-87, 2009 and several later publications by these authors. The non-propagating characteristic appears within a specific frequency band, referred to as a stopband. Therefore, the periodic texture and gap size must be designed to give a stopband that covers with the operating frequency band of the standard waveguide being considered in the calibration kit. It is also known that such stopbands can be provided by other types of periodic structures, as described in E. Rajo-Iglesias, P.-S. Kildal, “Numerical studies of bandwidth of parallel plate cut-off realized by bed of nails, corrugations and mushroom-type EBG for use in gap waveguides”, IET Microwaves, Antennas & Propagation, Vol. 5, No 3, pp. 282-289, March 2011. These stopband characteristics are also used to form so called gap waveguides as described in Per-Simon Kildal, “Waveguides and transmission lines in gaps between parallel conducting surfaces”, patent application No. PCT/EP2009/057743, 22 Jun. 2009.
It must be emphasized that any of the periodic or quasi-periodic textures previously used or that will be used in gap waveguides also can be used in a waveguide structure interconnecting arrangement, a flange adapter element or flange structure of the present invention, and is covered by the patent claims.
The concept of using a periodic texture to improve waveguide flanges is known from P.-S. Kildal, “Contactless flanges and shielded probes”, European patent application EP12168106.8, 15 May 2012.
According to the present invention, the two surfaces, e.g. the textured structure of the flange adapter element or a flange element, i.e. the plane formed by the free outer ends of the pins or ridges or similar of a periodic or quasiperiodic structure, and a smooth waveguide flange, or another textured surface, must not be separated more than a quarter of a wavelength of a transmitted signal, or rather have to be separated less than a quarter wavelength. This is thoroughly described in the above-mentioned publications, such as in particular in E. Rajo-Iglesias, P.-S.
Kildal, “Numerical studies of bandwidth of parallel plate cut-off realized by bed of nails, corrugations and mushroom-type EBG for use in gap waveguides”, IET Microwaves, Antennas & Propagation, Vol. 5, No 3, pp. 282-289, March 2011.
The periodic or quasi-periodic structure 15 in particular embodiments comprises an array of pins 151 with a cross section e.g. having the dimensions of 0.15λ×0.15, and a height of 0.15-0.25λ.
Through the provisioning of an interface formed by a smooth conductive surface of a waveguide flange 20 on one side of the interface and a textured surface 15 on the other side of the interface, power is prevented from leaking through the gap between the smooth conductive surface and the textured surface, or between two textured surfaces (see in particular embodiments described with reference to
According to the invention, by using a combination of a surface comprising a periodic or quasi-periodic structure 15 and a waveguide flange 20 with a smooth conductive surface, or two surfaces each provided with a periodic structure (see e.g.
Particularly the texture is designed to provide a stopband for waves leaking out between the two joining flanges, even when there is a small gap between the textured flange surface and the opposite flange surface, and also so that waves passing from the waveguide opening in one flange to the waveguide opening in the joining flange are not affected so that the transmission and the reflection from the joint is very close to the transmission and the reflection when conventional waveguide flanges are joined together, interconnected, very tightly by screws which are drawn very tight. As also referred to above, the texture can be made by pins, ridges or grooves etc. disposed around the waveguide opening in a pattern which is optimized to provide a good performance in terms of a low leakage, and improving, enhancing, the transmission coefficient which is reduced due to there being a discontinuity caused by the small gap between the two joining waveguides, and reducing the reflection coefficient which is increased due to there being a discontinuity caused by the small gap between the two joining waveguides.
PCT application PCT/SE2016/050277 with priority from Swedish patent application 1550412-9, filed on 4 Apr. 2015 by the same Applicant as for the present application, and the content of which herewith is incorporated herein by reference, shows an arrangement for connecting an analysing or measuring instrument to a waveguide calibration standard or a device under test, and a calibration arrangement for a tool or instrument for analysing or measuring microwave circuits or devices. It comprises a calibration connector element in the form of a disk or plate with a waveguide opening in it to be located between two joining waveguide flanges, allowing contactless connection between the two waveguide flanges, one of which being the port of the analysing or measuring instrument, e.g. a Vector Network Analyser (VNA), and the other being the port of either a waveguide calibration standard or a device under test. The calibration connector element comprises two surfaces, one on each side of it, each of which has a periodic or quasi-periodic structure around the waveguide opening forming a first and a second periodic or quasi-periodic structure. It is connectable between the waveguide flanges in such a way that on each side of it a gap is formed between the periodic or quasi-periodic structure and the smooth surface of the corresponding flange, hence allowing interchangeable contactless interconnection of a waveguide of the analysing or measuring instrument, e.g. a VNA, and a waveguide calibration standard or a device under test comprising a waveguide port.
The flange adapter element particularly is solid and made in one piece in order not to influence the signal flow. It may e.g. be made by moulding, casting, ablation, material assembling, e.g. micro-assembling and cutting is another method.
In
It is an advantage that, allowing a flange adapter to be fastened, e.g. by screws, to a waveguide flange, it will be kept in place, there is no risk of losing it, it will not fall off etc.
The height of the frame or rim sections 151B,152B is substantially the same as the height of the protruding elements 115B of the periodic or quasi-periodic structure 15B.
The flange adapter element 100B1 is adapted be connectable, fixedly or removably, to e.g. a standard waveguide flange 10B (cf.
The flange adapter element 100B1 comprises a central portion 170B provided with a periodic or quasi-periodic structure 15B comprising a plurality of protruding elements 115B, a textured surface, disposed around the opening of a standard rectangular waveguide opening 3B. In this embodiment the pins or protruding elements 115B each has a height, or length, corresponding to substantially half the total length of the pin or protruding element required to form the desired stop band. The total height is formed by the two flange adapter elements 100B1,100B2 disposed such that the textured surfaces face one another, and the total length being formed by two corresponding protruding elements 115B,115B, one on each flange adapter element (see
In still other alternative embodiments different heights are used for the sets of pins or protruding elements or corrugations on flange adapter elements. In yet other embodiments the lengths or heights of the pins or protruding elements, or corrugations, vary within the respective sets (not shown), as long as the total length of one another facing, or oppositely disposed, pins, protruding elements or corrugations corresponds to a length required for the desired stop band. Such different arrangements of protruding elements are disclosed in the European patent application “Waveguide and transmission lines in gaps between parallel conducting surfaces”, EP15186666.2, filed on 24 Sep. 2015 by the same Applicant, the content of which herewith is incorporated herein by reference, and which shows a microwave device which comprises two conducting layers arranged with a gap there between, wherein each of the layer comprises a set of complementary protruding elements, arranged in a periodic or quasi-periodic pattern and connected thereto, and which sets in combination for a texture for stopping wave propagation in a frequency band of operation in other directions than along intended waveguiding paths. When the lengths of the protruding elements are the same, and the full length of the texture being formed by two protruding elements arranged on each a conducting layer, the length of a protruding element hence corresponding to half the length of the full-length of the protruding elements of the texture.
Generally, throughout the application, the length of a full-length protruding element is approximately between λ/4 and λ/2, and the height of a so called half-length element, is substantially between λ/8 and λ/4, λ being the wavelength in free space or a dielectric media.
The flange adapter element 100B1 further comprises pairwise oppositely directed wing sections 175B,175B,176B,176B extending in four directions from the central portion 170B which here has a substantially octagonal cross-sectional shape. Each wing section 175B,175B,176B,176B is provided with a screw hole 102B adapted to receive an interconnecting screw 12B with a magnetic head (or screw head with a magnetic element as also discussed above) 13B (see
The air gap is smaller than λ/4, and the height of the protruding elements 115B, here half-length elements, is e.g. substantially λ/8.
In alternative embodiments the opposite pairs of protruding wing or flange sections have shapes as disclosed with reference to
A particular advantage with the use of half-height protruding elements is that only one type of flange or flange adapter element is needed instead of two different types involved in an interconnection, as e.g. in the case of a textured flange adapter element, as a separate element or fixed to, or forming part of, a waveguide flange, or a flange with such a texture, and a waveguide flange with a smooth surface. Thus gender-less flange adapter elements or waveguide flanges can be provided.
It should also be clear that the pattern of the textured surface, of the protruding elements forming the periodic or quasi-periodic structure, can be different, e.g. as shown with reference to
The flange adapter element 100B preferably comprises a solid part made of brass, Cu, Al or any other appropriate material with a good conductivity, a low resistivity and an appropriate density. It may for example be plated with e.g. Au or Ag in environments where further corrosion protection is needed. It should be clear that also other materials can be used, e.g. any appropriate alloy, or a plastic/polymer compound plated with e.g. Cu, Au or Ag.
Similar to the embodiment described with reference to
The flange adapter element 100C is adapted to provide an interconnection or joint between two waveguide structures with conventional smooth waveguide flanges 10C,20C (see
The flange adapter element 100C comprises a number of alignment pin receiving holes 101C; in the shown embodiment four, which are provided in a respective wing or flange section protruding from a central section 170C of the flange adapter element 100C where the textured surface 15C is located, in directions perpendicular to the direction of extension of the protruding elements 115C. The alignment pin receiving holes 101C serve the purpose of being adapted for receiving alignment pins (cf e.g.
Between two respective, opposite, pairs of protruding wing or flange sections, through recesses, here, waists 103C are formed by flange adapter side walls, perpendicular to the textured surface 15C, tapering towards a central region outside the textured surface 15C on a respective side thereof disposed outside the waveguide opening 3C short or narrow side walls. Between two respective, opposite, pairs of protruding wings or flange sections through recesses 102C are formed by flange adapter side walls perpendicular to the textured surface 15C, which recesses are substantially U-shaped with a substantially straight section interconnecting the legs of the U and located outside the textured surface 15C at locations extending substantially in parallel with the long, wide, sides of the waveguide opening 3C. The waist shaped recesses 103C and the U-shaped recesses 102C are so shaped, and have such dimensions, as to allow a fastening element 12C, or a head thereof, (cf.
In the following some different textured surfaces and surrounding rim or ridge sections will be described, applicable to any waveguide flange adapter element or waveguide flange etc.
The pins 115 can be thick or thin. Thick pins are preferable from a manufacturing point of view. A larger pin thickness to pin height ratio makes the production easier. However, standard flanges have a fixed size, so that there is a limited space to fit the pins in, and each row of pins introduces an attenuation for the waves preventing them from leaking out. Therefore, thin pins are preferable for a better performance of the flange, that is, for having less leakage. The inventive concept covers the use of thick as well as thin pins, or other protruding elements which are thick or thin.
As also mentioned with reference to
In
The designs presented by Pucci et. al showed to not be suitable to be produced at 60 GHz. One of the designs of the ridge is a rectangular rim with a thickness of λg/4 along the wide walls of the waveguide opening, and has a thickness of only 50 μm or even less along the narrow walls of the waveguide opening. Such a thickness is not appropriate from a manufacturing point of view. If on the other hand the thickness is increased, then it is not possible to cover the whole V-band of standard flanges (from 50 GHz to 75 GHz), which is a very wide band. This is due to a resonance appearing within the band.
Another design of a ridge around the waveguide opening is a circular rim that was used for a 200-300 GHz flange described in In S. Rahiminejad, E. Pucci, V. Vassilev, P.-S. Kildal, S. Haasl, P. Enoksson, “Polymer Gap adapter for contactless, Robust, and fast Measurements at 220-325 GHz”, Journal of Microelectromechanical Systems, Vol. 25, No. 1, February 2016, as also referred to above, which however is also not suitable for a V-band flange where the dimensions of pins and ridges are electrically larger in terms of wavelength. The size of the flange is fixed and limited, so there is basically no room to fit pins in the flange if a circular design for the ridge around the waveguide opening is adopted.
In
The length L or extension of the central ridge section or platform 151D′ can be optimized to give a good performance in terms of leakage within the frequency band of interest, in some embodiments e.g. 50-75 GHz. It has also been realized that there is a relation between the thickness of the rim or ridge 152D along the narrow side of the waveguide opening and the length of the ridge or platform 151D′. The larger the thickness of the short side rim or ridge 152D, the shorter the length L of the central ridge section, platform, 151D′.
For exemplifying reasons only, and by no means for limiting purposes, some exemplary dimensions are given for some different embodiments for a 60 GHz flange adapter element. In one embodiment thick pins are used having e.g. a diameter of about 670 μm, and a height of about 1110 μm (full height). The wall thickness may e.g. be 200 μm in H-plane (thickness of walls of short ridge section 152D and outer ridge sections, 151″), and λg/4 in E-plane, corresponding to the thickness of the wall of the central ridge section 151D′. The air gap may be about 100 μm and the flange may have a total thickness of about 6.6 mm.
In one embodiment for a 60 GHz flange adapter element thin pins are used having e.g. a diameter of about 400 μm. The wall thickness may e.g. be 200 μm in H-plane (thickness of walls of short ridge section 152D and outer ridge sections, 151″), and λg/4 in E-plane, corresponding to the thickness of the wall of the central ridge section 151D′. The air gap may be about 100 μm and the flange may have a total thickness of about 6.6 mm.
In still another embodiment for a 60 GHz flange adapter element thin pins are used having e.g. a diameter of about 400 μm and a wall thickness of about 300 μm in H-plane is used (thickness of walls of short ridge section 152D and outer ridge sections, 151″), and λg/4 in E-plane, corresponding to the thickness of the wall of the central ridge section 151D′. The air gap may be about 100 μm and the flange may have a total thickness of about 6.8 mm.
The length L or extension of the central ridge section or platform 151F′ can be optimized to have a good performance in terms of leakage within the frequency band of interest, in some embodiments e.g. 50-75 GHz. As also referred to above, there is a relation between the thickness of the rim or ridge 152F along the narrow side of the waveguide opening and the length of the ridge or platform 151F′ provided on the wide side. The larger the thickness of the short side rim or ridge 152F, the shorter the length L of the central ridge section, platform, 151F′ and vice versa.
As for the embodiment described with reference to
In
Here two different (and mirrored) shapes of interconnecting (or fastening) elements are used, first interconnecting elements 12G1, also called top/bottom fasteners, and second interconnecting elements 12G2, also called side fasteners. Thereby the semantic look is increased and the risk of incorrect mounting is reduced. Except for the outer shape, the design of the interconnecting elements 12G1, 12G2 is similar. In one embodiment they have a shell-shaped configuration 122 adapted to the shape e.g. of a WR15-flange. Internally they are provided with dome-shaped protrusions 121 adapted to allow connection to existing screw holes of the waveguide flange. On the front side cylindrical casings 123 are provided for reception of permanent magnet elements 13G, e.g. 3×2 mm neodymium magnets.
The interconnecting elements 12G1, 12G1,12G2,12G2 can easily be applied to a waveguide flange 10G, e.g. a WR15-flange by snapping them into place towards the centre of the flange 10G as shown in
They may then, are also, be attached by means of screws from the backside of the waveguide flange.
The interconnecting elements may e.g. be fabricated by means of jet moulding or liquid injection moulding. Of course also other fabrication methods are possible as well.
It should be clear that the invention is not limited to the illustrated embodiments but that it can be varied in a large number of ways, and features of the different embodiments can be freely combined. Particularly the periodic or quasi-periodic structures, textures, can be of many different kinds, i.e. the type, shape and size and arrangement of protruding elements, and the dimensions be scaled for different frequency bands, some figures are e.g. given for 60 GHz implementations as far as dimensions of protruding elements, thicknesses of ridge sections around the waveguide opening etc. are concerned. It should also be clear that a flange adapter element can be implemented as a separate part allowing releasable connection to waveguide flanges, guided and slidable by means of alignment pins, or comprise a waveguide flange itself, or be adapted for fixed connection to a waveguide flange. Flange adapter elements may also be provided as back-to-back flange adapter elements or single sided elements. Still further, interconnecting elements may comprise magnetic screw heads, or magnets connected to screw heads by means of gluing or similar, or magnetic elements attached to other interconnecting elements, as well as magnetic elements may be fastened on, or to, waveguide flanges or, particularly for flange adapter elements to be connected fixedly to a waveguide flange, or a flange support element (see e.g. reference numeral 145A in
In some embodiments the textured surface, i.e. the periodic or quasi-periodic structure, comprises a number of square shaped pins, with cross-sectional area dimension of (0.15λ)2 and a height of 0.15-0.25λ, surrounding a waveguide opening. It may also comprise a corrugated structure with a plurality of concentrically or elliptically disposed corrugations with grooves surrounding a waveguide opening.
As referred to above, the width, or cross-sectional dimension/the height of the pins or corrugations of any appropriate kind is determined by the desired frequency band. The higher the frequency band, the smaller the dimensions, and the dimensions scale linearly with the wavelength; the higher the frequency, the smaller the wavelength, and the smaller the dimensions. For a frequency band, by wavelength is here meant the wavelength of the centre frequency of the corresponding frequency band.
It is an advantage of the invention that, when magnetic interconnecting elements are used, a flange adapter element can be easily connected, loosened and reused in many different flange connections. It is also an advantage, that when e.g. magnetic elements are used, connection and release is much faster than if other fastening mechanisms are used.
The concepts of the present invention are also applicable to circular waveguides.
The concepts are also applicable to waveguide flanges which are not circular, but e.g. rectangular.
It particularly can be used for connecting a microwave or millimetre wave tool or instrument to a microwave or millimetre circuit or device, or a device under test (DUT) or a calibration arrangement for a tool or instrument for analysing or measuring microwave or millimetre circuits or devices. With a microwave instrument is here also meant devices for frequencies up to and above THz frequency.
It is an advantage that a waveguide interconnection arrangement is provided which facilitates interconnection using existing standard waveguide flanges.
The waveguide structure interconnecting arrangement further is compact and easy to assemble and reassemble—
It is also a particular advantage that the presence of a gap, enables relative displacement between the surfaces e.g. two textured surfaces or a textured surface and a smooth surface, which is of advantage in some implementations, e.g. during calibration procedures etc. when a flange needs to be moved.
It should be noted that the gap between surfaces is described as a gap, in some cases it may be substantially zero gap, the main point being that there is no requirement for any electrical contact between the two surfaces.
Claims
1.-39. (canceled)
40. An arrangement for interconnecting waveguide components, comprising:
- a number of waveguide flange adapter elements comprising a first surface of a conductive material with a periodic or quasi-periodic structure formed by a number of protruding elements that allow waves to pass across a gap between a second surface around a waveguide opening to another waveguide opening in a desired direction or waveguide path, at least in an intended frequency band of operation, and that stop propagation of waves in the gap in other directions;
- means for interconnecting a waveguide flange or a waveguide flange adapter element without requiring electrical contact and with assuring that the gap is present between the first surface and a third surface around the other waveguide opening of the other waveguide flange or of another waveguide flange adapter element, hence assuring that the first surface is not in direct mechanical contact with an opposite interconnecting waveguide flange or waveguide flange adapter element;
- wherein the gap is smaller than λ/4, where λ is a wavelength in a medium surrounding the protruding elements pins of a waveguide signal to be measured, and the interconnecting means comprises a rim, a ridge, a protective element or layer, or a supportive element or layer that at least partly surrounds surfaces formed by the periodically or quasi-periodically arranged protruding elements.
41. The arrangement of claim 40, further comprising at least one separate, loose, flange adapter element that is releasably disposed between two waveguide flanges interconnected.
42. The arrangement of claim 40, wherein at least one waveguide flange adapter element comprises alignment pin holes substantially symmetrically disposed around, and at a distance from, the first surface, and is aligned with respect to interconnecting waveguide flange or flanges by alignment pins introduced into the alignment pin holes and into cooperating pin holes in the interconnecting waveguide flanges.
43. The arrangement of claim 42, wherein the at least one waveguide flange adapter element is fixedly or releasably connected to a waveguide flange and is slidably arranged on the alignment pins.
44. The arrangement of claim 43, wherein the interconnecting means further comprises interconnecting elements; the at least one waveguide flange adapter element comprises a number of through recesses, protruding sections, or wing portions for receiving the interconnecting elements or portions thereof; the interconnecting elements are connected to at least one interconnecting waveguide flange; the interconnecting elements comprise magnetic elements or magnetic portions adapted for cooperating with magnetic elements of the other interconnecting waveguide flange or with magnetic elements or magnetic portions of interconnecting elements of the other interconnecting waveguide flange, at least some of the interconnecting elements include at least one of snap-on elements, clip-on elements, clamping elements, and fasteners with magnetic heads or elements fixedly or releasably connected thereto; and the at least one waveguide flange adapter element is interposed and aligned between two waveguide flanges, the waveguide flanges are interconnected and the waveguide flange adapter element is held therebetween.
45. The arrangement of claim 44, wherein the interconnecting elements comprise screws or sleeves with protruding portions; the waveguide flange adapter element has a thickness or height that corresponds to substantially twice a height of a screw head or a protruding portion; and interconnecting elements comprising screws are introduced into screw holes in both interconnecting waveguide flanges.
46. The arrangement of claim 43, wherein the at least one waveguide flange adapter element is interconnects two waveguide flanges with smooth surfaces; and the first surface faces one of the smooth waveguide flange surfaces such that the gap less is than λ/4.
47. The arrangement of claim 40, wherein the at least one waveguide flange adapter element is connected to a smooth waveguide flange by fasteners or glue such that the first surface faces away from the waveguide flange to which it is fastened.
48. The arrangement of claim 40, comprising two waveguide flange adapter elements, each comprising a first surface of a conductive material with a periodic or quasi-periodic structure formed by a number of protruding elements; each protruding element of a first set of protruding elements of a first one of the waveguide flange adapter elements faces a protruding element of a second set of protruding elements of the second one of waveguide flange adapter elements; facing protruding elements each have a height or length such that a total height or length of two facing protruding elements is a full length of the periodic or quasi-periodic structure needed to stop propagation of waves inside the gap between the flanges in any direction and to allow waves to pass across the gap from a waveguide opening in one flange surface to a waveguide opening in the other flange surface in an intended frequency band.
49. The arrangement of claim 48, wherein each waveguide flange adapter element comprises four protruding sections or wing sections disposed around its first surface and a hole adapted for receiving an interconnecting element.
50. The arrangement of claim 40, wherein the first surface of the at least one waveguide flange adapter element is optimized for low reflection coefficient and high transmission coefficient between two interconnected waveguide structures; and a height of a protruding element is either between substantially λ/4−λ/2 when the waveguide flange adapter element is interconnected with a waveguide flange with a smooth conductive surface or between λ/8−λ/4 when the waveguide flange adapter element is interconnected with another waveguide flange adapter element.
51. The arrangement of claim 50, further comprising rim or ridge sections that surround the first surface of the at least one waveguide flange adapter element, the rim or ridge sections comprising long rim or ridge sections and short rim or ridge sections that surround wide and narrow sides of the waveguide opening; wherein physical dimensions of the rim or ridge sections are selected with respect to one another; and a pattern of a periodic or quasi-periodic structure and the physical dimensions of the rim or ridge sections are selected with respect to one another to optimize electrical performance.
52. The arrangement of claim 51, wherein a wall thickness of a long rim or ridge section is about Δg/4, λg being a wavelength in the waveguide.
53. The arrangement of claim 40, wherein the protruding elements of the periodic or quasi-periodic structure are arranged in at least one row around the waveguide opening.
54. The arrangement of claim 40, wherein the periodic or quasi-periodic structure provides a stopband for waves leaking out between two interconnected waveguide flanges with the gap, such that waves passing from the waveguide opening in one flange to the waveguide opening in the interconnected flange are unaffected.
55. The arrangement of claim 40, wherein the protruding elements have dimensions and are arranged in a pattern adapted for a desired frequency band.
56. The arrangement of claim 40, comprising one first surface and a waveguide flange.
57. A surface structure, comprising:
- a periodic or quasi-periodic structure having a number of protruding elements for a waveguide flange as in claim 40;
- rim or ridge sections that surround a waveguide opening, around which the periodic or quasi-periodic structure is disposed, wherein the rim or ridge sections comprise long or wide rim or ridge sections and short or narrow rim or ridge sections that surround wide and narrow sides of the waveguide opening; physical dimensions of the rim or ridge sections and physical dimensions and arrangement of the number of protruding elements are selected with respect to one another based on electrical performance.
58. The surface structure of claim 57, wherein the number of protruding elements of the periodic or quasi-periodic structure are arranged in between one and four rows around the waveguide opening.
Type: Application
Filed: May 3, 2016
Publication Date: Apr 25, 2019
Applicant: Gapwaves AB (Göteborg)
Inventors: Simon Carlred (Västra Frölunda), Esperanza Alfonso Alós (Västra Frölunda), Per-Simon Kildal (Pixbo)
Application Number: 16/098,856