Polymer microwave fiber transceiver

Abstract

The present disclosure relates to a PMF transceiver (1) comprising a housing (2) having a recess (5) in which a printed circuit board (6) is arranged. The printed circuit board (6) comprises at least one radiating element (7) which in a mounted position is interconnected by a PMF interposer (13) and a PMF cable (18) associated therewith, the PMF interposer being arranged 5 between the printed circuit board (6) and the PMF cable (18) and comprising a main body (14) arranged in a cavity (17) in the housing (2). The PMF interposer (13) extends between the radiating element (7) and the PMF cable (19).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a Polymer Microwave Fiber Transceiver (hereinafter PMF Transceiver) for a data communication system based on Polymer Microwave Fiber transmission. BACKGROUND

[0002] WO19072571A1 was first published in the name of the same applicant in April 2019. It relates to an interconnect assembly for a switching device in a server room. It includes at least one cable having a core comprising a first dielectric material. The core is at least partially surrounded by a second dielectric material having a different index of refraction than the first dielectric material. A first connector portion is positioned relative to at least one antenna comprising a fan-out element. The fan-out element includes at least one hollow conductor per antenna arranged between the at least one antenna and the core of the at least one cable. The at least one hollow conductor extends in the fan-out element to guide signals between the at least one antenna and the core of the at least one cable. The hollow conductor has a first port aligned with the at least one antenna and a second port in communication with the core of the at least one cable in an assembled position. At least one second connector portion interconnects with the at least one cable, thereby positioning the core of the cable relative to the second port of the hollow conductor in a connected position.

[0003] WO18137997A1 was first published in the name of the same applicant in August 2018. It relates to a waveguide assembly including an elongated waveguide element and a connector body. The connector body is connected to one end of the elongated waveguide element and has a generally planar bottom surface and an opposing top surface. The connector body is made of a single piece of partially metalized dielectric. The connector body has a waveguide coupling element adjacent to the elongated waveguide element. The connector body also has an arrangement of electromagnetic bandgap elements adjacent to the waveguide coupling element.

[0004] US9478842BA was first published in the name of the California Institute of Technology in October 2016. The publication relates to a lens for interconnecting a metallic waveguide with a dielectric waveguide. The purpose is to minimize signal loss between the metallic waveguide and the dielectric waveguide.

[0005] US2014285293A2 was first published in September 2014 in the name of Texas Instruments Inc. It relates to a communication cable comprising a dielectric waveguide (DWG) having a dielectric core member having a first dielectric constant value and a cladding having a second dielectric constant value, the cladding surrounding the dielectric core member. The second dielectric constant value is lower than the first dielectric constant. An RJ45 compatible connector is attached to a mating end of the DWG. The RJ45 connector is configured to hold a complementary coupling mechanism on a mating end of a second DWG.

[0006] A paper published in IEEE JOURNAL OF SOLID-STATE CIRCUITS, vol. 46, no. 12, December 2011, entitled "A 12.5+12.5 Gb / s Full-Duplex Plastic Waveguide Interconnect" describes a plastic waveguide based interconnect. The system consists of a pair of transceivers and a plastic waveguide. Millimeter wave signals are transmitted in a low-cost long sheet solid plastic dielectric that acts as a waveguide. The plastic waveguide medium provides large bandwidth for data communication using millimeter wave carrier frequencies. It is described that the plastic waveguide interconnect does not require expensive electro- optical and optical-to-electrical conversion devices or precise alignment and provides longer transmission distances than wireless solutions due to better field confinement and lower path loss.

[0007] A paper published at GeMiC 2018, March 12-14, Freiburg, Germany, entitled "Design and Characterization of a Compact and Robust Shielded Dielectric Waveguide for mmW Applications" describes a dielectric waveguide concept for mmW frequencies. To avoid typical problems of open structure waveguides like unshielded dielectric waveguides, a compact and still flexible design is proposed. To provide experimental results, a waveguide transition from a metallic rectangular to a circular dielectric waveguide is characterized. SUMMARY

[0008] In the following, the term PMF means polymer microwave fiber. The opportunity to transmit high data rates at typical wavelengths in the millimeter range using only a simple plastic strip as PMF waveguide element at frequencies in the range of e.g. 100 GHZ to 200 GHZ has created a lot of research activities in the past.

[0009] Early attempts, as described for example in the first paper mentioned above, did indeed concentrate on the general feasibility of signal transmission and ignored the practical problems caused by a considerable portion of the electromagnetic wave propagating outside the plastic strip and would lead to a significant negative leakage. One possibility to overcome this problem is to arrange the plastic strip with sufficient spacing to other objects and especially to other dielectric waveguides. While this would be the simplest way to solve the problem, it would not be applicable to an external laboratory setup, because there are several disadvantages in practical use: the mechanical stability of the plastic strip with a cross section in the range of about 0.5 mm to 3 mm limits the length of the waveguide to a few centimeters. Furthermore, using any object touching or even approaching the waveguide, or even being contaminated by dust particles in the surrounding atmosphere, would lead to significant signal loss and distortion. The reliable fixation of the waveguide is not solved. Therefore, in a laboratory environment, the plastic strip is often just a stick in the overall transmission structure.

[0010] Another more practical attempt is to surround the plastic strip acting as a waveguide with a protective cladding. However, in this case other disadvantages occur: in order to concentrate the field in the plastic strip, the permittivity of the cladding needs to be significantly smaller than the permittivity of the core. In addition, the cladding diameter usually needs to be large enough so that the external electromagnetic leakage decays to an acceptable level. This field decay (leakage) depends on the permittivity difference between the core and the cladding. However, if a resonant structure - this can be a metallic or dielectric section with a size of several half- wavelengths - will approach the outer surface of the cladding, the resonance will increase by several orders of magnitude even with weak coupling. For a low-loss waveguide operating for example in the range of 110 GHz to 140 GHz, this would usually lead to a cladding with a diameter in the range of 6 mm to 10 mm.

[0011] In another attempt described in the second paper mentioned above, the plastic waveguide is surrounded by a protective cladding and a metallic shield. While the advantages would be a stable signal transmission independent of surrounding environmental objects, touching and cross-talk, and a certain reduction of the overall dielectric cable diameter, the disadvantages are a significant increase in complexity and a much higher effort in manufacturing, because the multimodal propagation can lead to severe spreading problems. A commercially applicable plastic waveguide solution should remain simple and cost-efficient compared to other data cable solutions such as for example twisted pair cables.

[0012] Therefore, when moving from a simple plastic strip, as can be applicable in a laboratory setup, to a robust product applicable for mass production, some additional problems have to be solved.

[0013] The outer diameter of a polymer microwave fiber cable depends strongly on the operating wavelength. However, using a specific material combination, the outer cable size can be reduced. Because all known dielectric materials with a relative permittivity higher than 2.6 have a high loss tangent factor, or even several orders of magnitude higher than low-loss materials such as PTFE, PP or PE. In addition to the loss tangent, for higher permittivity materials, the reduced propagation speed of the wave leads to an increase in loss only through a virtual increase in cable length. Increasing the operating frequency will lead to a smaller operating wavelength and thus allow to reduce the cable diameter in a linear fashion (e.g. double the operating frequency = half the cable diameter) to maintain low-loss / low-permittivity materials, but today's low-cost mass-silicon-based semiconductor technology is limited to a maximum operating frequency somewhere between about 140 GHz and 170 GHz. At these frequencies, a clad DWG cable will end up with an outer diameter of > 5 mm to 7 mm. A shielding structure that protects the cable from touch sensitivity and crosstalk will definitely make the transmission more robust, even when the cladding diameter is reduced but with an additional metal foil and jacket, the outer cable diameter will still remain above 5 mm.

[0014] The necessary typical size of a transceiver silicon chip is significantly smaller - typically in the range of 1 mm by 1 mm - when compared to the diameter of a cable in the range of 5 mm to 7 mm made of low-loss materials at 140 GHz. A high-speed data transceiver should be located on a PCB as close as possible to the components acting as data source / data sink, because the maximum routing distance of a high-speed bus is usually limited (typically 25 GBit / s < 25 cm) and cost driven. For duplex operation and / or parallelization, multiple cable links can be required, so that the necessary space for the cables leads to strong design limitations. A fan-out element implemented as an air-filled metal waveguide as proposed in WO2019072571A1 of the same applicant solves this problem.

[0015] With an appropriate material combination of different dielectric permittivity as described in PCT / EP2019 / 084547 of the same applicant - which is incorporated herein by reference with respect to PMF cables - the electromagnetic field can be significantly more confined in the fiber core, allowing for a much thinner dielectric waveguide diameter. The accompanying deterioration of waveguide attenuation usually prevents the use of very thin PMF cables over longer distances. However, to implement a fan-out section bridging a few centimeters or decimeters, such PMF cables do offer an attractive option, but the additional sections with additional interfaces will increase the number of sections, material and assembly costs and the number of misalignment tolerances and failure options.

[0016] To solve the problems set forth above, a PMF transceiver according to the present disclosure comprises a housing having a recess, a printed circuit board (also referred to as PCB) is arranged with respect to the housing and positioned in the recess. The printed circuit board comprises or is interconnected with at least one radiating element. The radiating element is interconnected with a PMF cable in an installed position (during operation) by a PMF interposer which will be described in more detail below. The PMF interposer is arranged in the housing between the radiating element (antenna) and the PMF cable. The PMF interposer typically comprises a main body arranged in a cavity of the housing and / or a further portion extending between the radiating element and the PMF cable in a longitudinal direction of the housing. The PMF interposer can be arranged coaxially with respect to the cavity. Other arrangements are possible. The interposer can have a polarization maintaining cross section (e.g. rectangular or elliptical) or a circular cross section which does not maintain polarization.

[0017] The cavity can have a constant and / or variable cross section over the length of the interposer. The cavity preferably comprises an electrically conductive surface that acts as a shield for the signals transmitted by the interposer between the radiating element and the core of the PMF cable. The electrically conductive surface is preferably arranged in the direction of the interposer. Good results can be achieved when the housing is made of a metal alloy, for example by means of die casting. In a preferred and easy to assemble variant, the housing comprises a lower part and an upper part that in the assembled position are interconnected along at least partly mutually corresponding first and second interaction surfaces. The cavity extends in and along said first and second interaction surfaces. When disassembled, a first half of the cavity is arranged in the upper part of the housing and a second half is arranged in the lower part of the housing. If appropriate, an EBG structure extends along the cavity in said first and second interaction surfaces. An EBG structure refers to an electromagnetic band gap structure that creates a stop band to block certain frequency bands of electromagnetic waves. The EBG structure can be achieved, for example, by a fine, periodic pattern of small metal patches or drillings in the upper part and / or lower part of the housing. To reduce manufacturing costs, good results can be achieved when the housing is made by means of die casting. However, in mass production, the achievable accuracy and tolerances are moderate. As mentioned above, the interposer can significantly contribute to withstand rough tolerances. Limited accuracy can result in gap sizes between housing elements that will not provide sufficient isolation within millimeter wave frequencies. Therefore, a specific EBG structure is foreseen that is, for example, slide symmetric to achieve significantly better cross-talk isolation. The PMF interposer can comprise a compensation structure to compensate for a mismatch between the impedance of the PMF interposer and the impedance of the PMF cable. Good results can be achieved when the compensation structure is arranged at the end of the PMF interposer in the direction of the core of the PMF cable. In a preferred variant, the main body of the PMF interposer is a spatially curved s-shape to compensate for a lateral offset of the main axis of the radiating element and the core of the PMF cable. Good results can be achieved when the PMF interposer is arranged in the cavity in a pre-tensioned manner. For good signal transmission, the PMF interposer can be arranged to press against the PMF cable in the mounted position. The PMF interposer can comprise at least one support element to position the PMF interposer relative to the cavity. Good results can be achieved when the PMF interposer is interconnected with the radiating element (source and / or sink of the signal) by means of a horn antenna. To reduce manufacturing costs, the PMF interposer can be made by means of injection molding of a plastic material. Depending on the field of application, the PMF interposer can be made by means of two-component injection molding. The housing can form part of an antenna.

[0018] The PMF-interposer offers the advantage of higher performance and significantly reduced complexity to a single part, which can preferably be made of plastic material as mentioned above and in the following. The PMF-interposer can solve at least one of the following aspects: it forms part of a waveguide fan-out structure between a dense antenna structure of one or more co-located transmitter and / or receiver components and a larger diameter PMF cable group or bundle. If appropriate, this waveguide can comprise multiple dielectric constant regions as described in the above cited application PCT / EP2019 / 084547, i.e. for flattening group delay variation. In a preferred variant, multiple dielectric constant regions can be realized, e.g. by a bi-component injection molding and / or foaming and / or micro-structured section that reduces the dielectric constant in the desired regions. If needed, groups of multiple PMF-interposers can be realized in one single part. Furthermore, these elements can be designed as spring elements, allowing to compensate for tolerances from all involved parts. Additional filament positioning elements can be used to group multiple interposers. The reduced number of involved parts and the self-alignment structure help to keep mechanical tolerances under control. The PMF-interposer can act as an RF compensation structure towards the PMF cable, ideally providing impedance matching according to the desired H11 mode in both waveguides, without the need for forward and backward transformation in the metallic TE01 waveguide mode. This will improve the coupling of electromagnetic energy, reduce losses, multi-mode interference and reduce the risk of coupling to undesired interference. Furthermore, it allows to open up mechanical misalignment tolerances for signal transmission and still maintain the desired transmission conditions. Optionally, the variable length of stretchable or elastic sections can further ease handling of mechanical tolerances along the transmission direction. For attaching the PMF cable to the housing in a fixed manner, the housing can comprise a mount that fixes the PMF cable, e.g. by glue. Other variants are possible. The mount is typically arranged at the opposite end of the housing with respect to the PCB. A PMF assembly according to the present disclosure typically comprises at least one PMF transceiver as described above and in the following and a PMF cable interconnected with the PMF transceiver in the mounted position. Good results can be achieved when the PMF transceiver and the PMF cable are interconnected with each other in a fixed manner and / or when the transceiver is interconnected with the cable in the described manner at each end of the PMF cable. In a preferred variant, the PMF assembly comprises two PMF cables arranged substantially parallel with respect to each other, with each cable at both ends pointing to a PMF transceiver as described herein. Depending on the field of application, the PMF transceiver can be designed to be interconnected with a single cable, with two cables or more cables. It is conceivable that the PMF transceiver transmits and / or receives data.

[0019] Compact, hot-pluggable interface modules known as "small form-factor pluggable" (SFP standard) transceivers are widely used in high-speed Ethernet data communications between devices in telecommunications and data communications. With the gradual development of data rates, further partially downward compatible variants with higher speed classes (e.g. SFP+) are developed; among them SFP28, QSFP and QSFP56. There are three different types of physical data transmission today: passive direct-attached copper cables, active direct-attached copper cables and active optical cables.

[0020] Active polymer microwave fiber (PMF) devices and modules according to the present disclosure bridge the gap between expensive optical technology for high data rate long range and transmission based on multi-biaxial copper cables that are usually cheaper, limited in data rate and cable length. PMF variants can provide even lower cost compared to copper cables while still allowing operation at higher data rates and / or cable lengths.

[0021] To achieve this goal, a lowest electrical loss material with a low dielectric constant is generally the most desirable cable base polymer. Good results can be achieved by materials from the polymer group of polyolefins (e.g. polyethylene, polypropylene). These materials provide a relatively low electrical loss and environmental robust behavior, but also a low cost polymer.

[0022] To operate in full duplex operation or to increase the data rate, it is generally desirable to use two waveguide cables per PMF transceiver, e.g. in the form of SFP modules. Unfortunately, the low loss requirement at a target operating frequency range of about 130 GHz requires a cable outer diameter of more than 5 mm. Thus, it is not possible to feed two parallel cables directly into the standardized dimensions of an SFP module, because a side-by-side cable arrangement of two cables, whereby each cable has a diameter of e.g. 6.5 mm in front of the connector, would fit into the minimum connector pitch of 13.4 mm between SFP modules. This problem can be solved by a PMF interposer that is needed by the bridging geometry.

[0023] In a preferred variant, a printed circuit board (PCB) arranged inside the SFP typically comprises the associated electronics for high-speed multi-port connection and at least one mm-wave antenna for transmitting and / or receiving signals. The height of the SFP module is defined by the standard for SFP modules. Side firing antennas, such as Vivaldi or SIW horn antennas, need to be interconnected with the PMF cable, respectively its central axis. To overcome the problem that PMF cables with a diameter of e.g. 6.5 mm cannot be placed ending inside the standard SFP module due to limited dimensions, the present disclosure foresees a so-called PMF interposer interconnecting the antenna, preferably arranged on the PCB, with the PMF cable end that can be positioned outside the SFP cage.

[0024] The RF compensation structure provides an impedance match between the antenna's impedance and the PMF interposer, if appropriate. This compensation structure can be designed to be self-aligned between the antenna and the PMF interposer. This helps to reduce transmission distortion (S-parameter degradation in forward and backward direction) even when misalignment occurs due to possible product tolerances.

[0025] In a preferred variant, the antenna is merged into a H-plane substrate integrated horn antenna (preferably a PCB SIW horn) elongated by a metal horn discharging into a metal cavity acting as a shield for a dielectric waveguide, can provide perfect cross-talk isolation between adjacent channels to avoid distortions caused by multi-mode propagation and / or cavity resonance, it is important that the antenna only excites the desired H11 mode in the interposer. Any abrupt permittivity change generates a field distortion that excites unwanted other modes. The transition from the PCB SIW horn to the air-filled metal horn causes an impedance step, and further, the air-filled metal horn to the (high permittivity) PMF interposer again causes an impedance step. An integrated RF compensation structure, possibly integrated on the tip of the interposer by injection molding, can broadband compensate such impedance steps and thus significantly improve the otherwise severely degraded S-parameters of this launcher.

[0026] The drawback of impedance steps is often neglected in literature using Vivaldi antennas (e.g. directly attached to the PMF cable without air gap in laboratory conditions), but this type of launcher suffers from cavity resonance when a metal shielding structure fully surrounding the Vivaldi antenna becomes mandatory (e.g. in tight side-by-side arrangements).

[0027] Furthermore, an integrated RF compensation structure (e.g. lens) can provide impedance matching between the PMF interposer and the PMF cable impedance. The higher dielectric constant material of the PMF interposer compared to the dielectric constant of the cable cores, and the gap between the two cores caused by the tolerance of the surrounding air around the interposer compared to the higher dielectric constant cladding in the PMF cable, will result in severe S-parameter deterioration and cavity mode resonances. An integrated RF compensation structure (e.g. lens) molded on the tip of the interposer can reduce transmission distortion even when misalignment introduced by (low cost) production tolerances occurs.

[0028] Furthermore, an integrated filament support element that is almost transparent to electromagnetic waves can position and hold the PMF interposer in the designed position without reducing the field confinement like any cladding material. Spring loaded bending of the support element can compensate for mechanical tolerances, thus helping to control the air gap between the interposer and the antenna or the interposer and the PMF cable. Further optionally, a flexible section of the interposer can allow to control both air gaps.

[0029] The higher dielectric constant material for the PMF interposer allows for a greater field confinement and thus a thinner waveguide. Since the length of the PMF interposer is rather small compared to the length of the cable, the increase of the total attenuation remains small. Relative dielectric constant values from e.g. 3...100 can be used, whereby the diameter of the PMF interposer waveguide follows the square root of the relative dielectric constant values.

[0030] It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding, and are incorporated and constitute part of this specification. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operation of the concepts disclosed. BRIEF DESCRIPTION OF DRAWINGS

[0031] The disclosure described herein will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0032] Figure 1 PMF transceiver shown in perspective view, partly cut open;

[0033] Figure 2 PMF transceiver according to Figure 1 in exploded view;

[0034] Figure 3 PMF transceiver as SFP module in unplugged state;

[0035] Figure 4Plug-in PMF transceiver according to the Figure 3 invention. DETAILED DESCRIPTION

[0036] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, the embodiments disclosed herein can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Wherever possible, like reference numerals will be used to refer to like components or parts.

[0037] Figure 1 A PMF transceiver 1 according to the present disclosure is shown in a perspective view from above. The PMF transceiver 1 is shown in a partly cut-away view. Figure 2 The PMF transceiver 1 is shown in an exploded view. The disassembly direction is indicated by the dashed line. Figure 3 The PMF transceiver 1 is shown from below in an unplugged state at a distance from a suitable socket 26. Figure 4 The PMF transceiver 1 is shown in a plugged state with the socket 26. In the variant shown, the PMF transceiver 1 comprises a housing 2 with a recess 5 in which a printed circuit board 6 (PCB) is arranged and can be accessible from the outside for electrical interconnections. As indicated, the housing 2 comprises a lower part 3 and an upper part 4 which in the assembled position are interconnected along a first interaction surface 9 and a second interaction surface 10. The printed circuit board 6 comprises at least one radiating element 7 which in the mounted position is interconnected by a PMF interposer 13 and a PMF cable 19 associated with the at least one radiating element, the PMF interposer being arranged between the printed circuit board 6 and the PMF cable 19. In the variant shown, the radiating element 7 is coupled to the back end of the interposer by an antenna 8. The back end of the interposer and / or the cavity can form part of the antenna 8. The PMF cable 19 generally comprises a core 20 surrounded by a cladding 21. In the drawing, only a small section of the cable is shown. Good results can be achieved when the cable 19 is of the type as described in PCT / EP2019 / 084547 which is incorporated by reference into the present application. In the variant shown, the PMF transceiver is designed to be connected to two cables 19 which are arranged substantially in parallel. The two cables 19 are interconnected with the respective radiating elements 7 by a PMF interposer 13 which will be described in more detail below. The PMF interposer 13 comprises a main body 14 which in the mounted position (see Figure 1) is arranged in a cavity 17 in the housing 2, which cavity extends between the radiating element 7 and the PMF cable 19. The PMF interposer 13 is arranged in the cavity 17. The cavity 17 comprises an electrically conductive inner surface 18, which acts as a shield for the signals transmitted by the interposer 13 between the radiating element 7 and the core 20 of the PMF cable 19. The electrically conductive inner surface 18 can be obtained because the material of the housing is sufficiently electrically conductive, for example in the form of a suitable metal alloy and / or coating (not shown in detail) of the surfaces of the cavity. In the variant shown, the cavity 17 extends in and along the first and second interaction surfaces 9, 10. Substantially half of the cavity 17 is arranged in the lower and upper portions 3, 4 of the housing 2. To compensate for tolerances, an EBG structure 11 formed by a series of drillings extends along the cavity 17 in the first and second interaction surfaces 9, 10. If appropriate, the PMF interposer 13 can comprise a compensation structure 15 to compensate for a mismatch between the impedance of the PMF interposer 13 and the impedance of the PMF cable 19. In the variant shown, the compensation structure 15 is lenticular-shaped arranged at the end of the PMF interposer 13 in the direction of the core 20 of the PMF cable 19. Other arrangements are possible depending on the design. The compensation structure 15 can be designed to act as an electromagnetic field shaping structure. To compensate for a geometrical mismatch between the axes of the radiating elements 7, respectively the antennas 8, the main body 14 of the PMF interposer 13 can be curved in an s-shape, as shown. Good results can be achieved when the PMF interposer 13 is arranged in the cavity 17 in a pre-tensioned manner relative to the longitudinal direction of the cavity. To optimize the signal transmission, the PMF interposer 13 can be arranged to press against the PMF cable 19 in the mounted position. As shown, the PMF interposer 13 can comprise at least one support element 16 to position the PMF interposer 13 relative to the cavity 17. In the variant shown, the support structure comprises a thing leg 17 extending in the radial direction. Good results can be achieved when the PMF interposer 13 is interconnected by the horn antenna 8 with the radiating element 7. The housing 2 can form part of the horn antenna. Alternatively, or additionally, other elements can form part of the horn antenna 8. The PMF interposer 13 is made by injection molding of a single-component plastic material or by multi-component injection molding. The housing 2 is preferably made by die casting of a metal alloy. To attach the cable, the housing 2 can comprise a mount 22 to fix the PMF cable 19 to the housing 2. In the variant shown, the PMF transceiver is designed according to the standard of an SFP module (SFP = Small Form-factor Pluggable). In Figure 3 , the PMF transceiver 1 is arranged outside a corresponding socket 26, and in Figure 4In the middle, the PMF transceiver 1 is shown in a plugged state inside the socket 26. When the printed circuit board 6 and the elements (not visible) arranged thereon are arranged inside the socket 26 in the plugged state, the PMF cable 19 - respectively for their base 22 - is arranged outside the socket 26. The distance between the printed circuit board 6 - respectively the active elements interconnected therewith - and the PMF cable 19 is bridged by the PMF interposer 13, as described above and claimed in the following. The PMF cable 19 does not need to reach inside the socket 26.

[0038] More specifically, the words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure.

[0039] List of names

[0040] 1. Polymer microwave fiber transceiver (PMF transceiver)

[0041] 2. Housing

[0042] 3. Lower part (housing)

[0043] 4. Upper part (housing)

[0044] 5. Concave (for PCB)

[0045] 6. Printed circuit board (PCB)

[0046] 7. Radiating element (PCB)

[0047] 8. Antenna (PCB)

[0048] 9. First interaction surface (lower part, housing)

[0049] 10. Second interaction surface (upper part, housing)

[0050] 11. Electromagnetic bandgap structure (EBG structure)

[0051] 13. PMF interposer

[0052] 14. Main body (PMF interposer)

[0053] 15. Lens (PMF interposer)

[0054] 16. Support element, bracket (PMF interposer)

[0055] 17. Cavity (housing)

[0056] 18. Conductive inner surface (cavity)

[0057] 19. PMF cable

[0058] 20. Core (PMF cable)

[0059] 21. Cladding (PMF cable)

[0060] 22. Base (housing) for PMF cable

[0061] 23. Indent (base for PMF cable)

[0062] 24. Bracket (base for PMF cable)

[0063] 25. PMF assembly

[0064] 26. Plug (for PMF transceiver)

Claims

1. PMF transceiver (1) comprising a. a housing (2) having a recess (5) in which a printed circuit board (6) is arranged, b. at least one radiating element (7) which in mounted position is interconnected by a PMF interposer (13) and a PMF cable (19) associated therewith, the PMF interposer being arranged between the radiating element (7) and the PMF cable (19) and comprising a main body (14) arranged in a cavity (17) in the housing (2), the cavity extending between the radiating element (7) and the PMF cable (19).

2. PMF transceiver (1) according to claim 1, wherein the PMF interposer (13) is completely surrounded by the cavity (17).

3. PMF transceiver (1) according to any one of the preceding claims, wherein the cavity (17) comprises a conductive surface (18) which acts as a shield for signals transmitted by the interposer (13) between the radiating element (7) and the core (20) of the PMF cable (19).

4. PMF transceiver (1) according to claim 1 or 2, wherein the housing (2) comprises a lower part (3) and an upper part (4) which are interconnected along first and second interaction surfaces (9, 10).

5. PMF transceiver (1) according to claim 4, wherein the cavity (17) extends in and along the first and second interaction surfaces (9, 10).

6. PMF transceiver (1) according to claim 5, wherein an EBG structure (11) extends along the cavity (17) in the first and second interaction surfaces (9, 10).

7. PMF transceiver (1) according to claim 3, wherein the PMF interposer (13) comprises a compensation structure (15) to compensate for a mismatch between the impedance of the PMF interposer (13) and the impedance of the PMF cable (19).

8. PMF transceiver (1) according to claim 7, wherein the compensation structure (15) is arranged at one end of the PMF interposer (13) in the direction of the core (20) of the PMF cable (19).

9. PMF transceiver (1) according to claim 1 or 2, wherein the main body (14) of the PMF interposer (13) is a curved s-shape.

10. PMF transceiver (1) according to claim 1 or 2, wherein the PMF interposer (13) is arranged in the cavity (17) in a pre-tensioned manner.

11. PMF transceiver (1) according to claim 1 or 2, wherein the PMF interposer (13) in mounted position is pressed against the PMF cable (19).

12. PMF transceiver (1) according to claim 1 or 2, wherein the main body (14) of the PMF interposer (13) comprises a polarization-maintaining cross-section or a circular cross-section.

13. The PMF transceiver (1) according to claim 1 or 2, wherein the PMF interposer (13) comprises at least one support element (16) to position the PMF interposer (13) relative to the cavity (17).

14. The PMF transceiver (1) according to claim 1 or 2, wherein the PMF interposer (13) is interconnected with the radiating element (7) by a horn antenna (8).

15. The PMF transceiver (1) according to claim 14, wherein the PMF interposer (13) and / or the cavity (17) form a part of the horn antenna (8).

16. The PMF transceiver (1) according to claim 1 or 2, wherein the PMF interposer (13) is made by injection molding of a plastic material.

17. The PMF transceiver (1) according to claim 1 or 2, wherein the housing (2) is at least partially made by die casting of a metal alloy.

18. The PMF transceiver (1) according to claim 1 or 2, wherein the housing (2) comprises a mount (22) to fix the PMF cable (19) to the housing (2).

19. The PMF transceiver (1) according to claim 1 or 2, wherein the PMF transceiver (1) is designed as a hot-pluggable interface module according to the SFP standard.

20. PMF assembly (25) comprising at least one PMF transceiver (1) according to any of the preceding claims and a PMF cable (19) interconnected with the PMF transceiver (1) in a mounted position.

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