Patent Publication Number: US-11024975-B2

Title: Multi-band orthomode transducer device

Description:
FIELD OF THE DISCLOSURE 
     Embodiments of the present disclosure relates to a multi-band orthomode transducer device. 
     BACKGROUND 
     Modern communication systems comprise devices that communicate over-the-air, for instance via satellites. The respective devices may comprise dual-polarized antennas, for instance horn antennas, which are connected with waveguides in order to process the respective signals. 
     Those antennas require orthomode transducers (OMTs), corresponding to waveguide components, are used either to combine or to separate two orthogonally polarized signal portions of the respective signals. In other words, the orthomode transducers overlay or rather separate two orthogonal modes, for instance a horizontally polarized mode and a vertically polarized mode, onto the same waveguide. 
     Even though the dual-polarized antennas combined with the orthomode transducers have good performance characteristics such as a stable half-power beamwidth (HPBW) and phase center, the respective bandwidth is limited due to constraints of the waveguide physics, namely cut-off and higher-order modes, or due to directivity/HPBW changing significantly with frequency. However, the signals used may have a large bandwidth. Thus, several orthomode transducers with orthogonally polarized antennas assigned thereto have to be used in order to measure several different frequencies, which results in complex systems. Further, this yields problems in an automated system for feed switching while leading to cable-bending or very large energy chains. 
     Accordingly, there is a need for a possibility to measure several different frequencies in an easy and efficient manner. 
     SUMMARY 
     Embodiments of the present disclosure provide a multi-band orthomode transducer device with a three-dimensional housing, the three-dimensional housing encompassing at least two orthomode transducers. Each orthomode transducer is assigned to three ports of which a first port is assigned to a first polarization, a second port is assigned to a second polarization and a third port is assigned to a combination of the first and second polarizations. Each of the orthomode transducers has a waveguide connected with the three ports. The waveguides of the orthomode transducers are located in the three-dimensional housing without intersecting each other. 
     Accordingly, a compact multi-band orthomode transducer device is provided that has two or more orthomode transducers, for instance three orthomode transducers, housed in a common three-dimensional housing. In other words, the orthomode transducers are integrated in the single three-dimensional housing of the multi-band orthomode transducer device. 
     The first and the second polarizations may be orthogonal with respect to each other. Thus, each orthomode transducer of the multi-band orthomode transducer device may split a respective signal received into two components that are polarized orthogonally with respect to each other. 
     As the orthomode transducers are located within the three-dimensional housing without intersecting each other, the signals or rather signal portions processed by the orthomode transducers do not interfere with each other. Accordingly, each orthomode transducer can be assigned to a respective frequency range (frequency band) of the entire bandwidth covered by the multiple-band orthomode transducer device. In fact, no internal intersection of the waveguides occur within the multi-band orthomode transducer device, particularly its housing. In other words, the orthomode transducer device is a multi-band orthomode transducer device, as the several orthomode transducers located within the three-dimensional housing are assigned to a respective separate frequency band resulting in several separate frequency bands that can be processed by the single multi-band orthomode transducer device. 
     According to an aspect, the first port relates to a first output port and the second port relates to a second output port. The third port of each orthomode transducer may relate to a feed port via which randomly polarized signals may be fed to the respective orthomode transducer, which splits the respective signals into two signal portions with different polarizations, which are forwarded to the first port and the second port, respectively. Hence, each orthomode transducer outputs via its output ports the respective split signal portions that are polarized orthogonally with respect to each other. 
     Alternatively, the first port relates to a first feed port and the second port relates to a second feed port. The third port of each orthomode transducer may relate to a single output port. Hence, differently polarized, particularly orthogonally polarized, signals are combined by each orthomode transducer such that the combined signal obtained can be outputted via the third port, namely the single output port. 
     Another aspect provides that the first port of each orthomode transducer is opposite to the respective third port. Thus, the respective waveguide of each orthomode transducer runs between the first and the third ports in a straight manner, as the respective ports are located opposite to each other. In fact, the waveguide located between the respective first and third ports comprises at least a straight line portion. 
     Further, the respective first ports may be located in different planes being parallel to a base area of the multi-band orthomode transducer device, particularly the housing. In other words, the respective first ports are located in different heights with respect to the ground of the multi-band orthomode transducer device. This arrangement of the respective first ports also ensures that the respective waveguides of the orthomode transducer do not intersect with each other. 
     As the respective first ports are located in different planes and the third ports are opposite to the respective first ports, the third ports are also located in different planes that are parallel to the base area of the multi-band orthomode transducer device. In fact, the first ports and the third ports of each orthomode transducer are located in the same plane being parallel to the base area. 
     In addition, the respective second ports are located at a common side of the three-dimensional housing. Thus, the second ports of the different orthomode transducers are located at the same side of the three-dimensional housing so that the second ports can be connected easily, namely via a common side of the multi-band orthomode transducer device. 
     According to another aspect, the respective second ports are located in a common plane being parallel to a base area of the multi-band orthomode transducer device. The respective common plane may be opposite to the base area of the multi-band orthomode transducer device. In other words, the common plane corresponds to the top plane of the three-dimensional housing that is opposite to the base area of the housing. However, the second ports may also be located at the base area, namely the respective base surface of the housing, as the base area is parallel to itself. 
     The first ports may be perpendicularly orientated with respect to the second ports. Hence, the first ports (as well as the third ports) may be located at sides that are perpendicular with respect to the common side at which the respective second ports are located. As the second ports may be located at the top of the three-dimensional housing, the first ports (as well as the third ports) may be located at face sides or rather lateral side(s) of the respective three-dimensional housing. 
     As mentioned above, the first and second ports are assigned to different polarized signals, particularly orthogonally polarized signals. Hence, the first and second ports are orientated orthogonally with respect to each other in order to simplify combination or rather separation of the respective signals or rather signal portions. 
     According to an embodiment, the first and second ports each are shaped rectangularly. Thus, rectangular waveguides may be connected with the first and second ports. Via the first and second ports, the respective signals polarized orthogonally with respect to each other may be forwarded to or rather received from a network processing the respective signals. 
     Another aspect provides that the third ports are shaped circularly. Hence, antennas or other structures with circular interfaces may be connected with the third ports. For instance, horn antennas may be connected with the third ports or coaxial structures. 
     Hence, an integrated rectangular to circular transition is provided, as the third ports are shaped circularly, whereas the first and second ports are shaped rectangularly. The respective rectangular to circular transition may be established by the respective waveguide of the orthomode transducers, particularly the interfaces merging into the respective ports. 
     Generally, a network may provide orthogonally polarized signals processed via the first and second ports of the respective orthomode transducer in order to combine the orthogonally polarized signals resulting in a combined signal outputted via the third port of the orthomode transducer. 
     Alternatively or additionally, namely in another operation mode, signals are received via the third port, which are split by the respective orthomode transducer in order to separate the respective signals in orthogonally polarized signals forwarded to the network via the first and second ports. 
     According to another aspect, the at least two orthomode transducers are assigned to separate frequency bands. Thus, the multi-band orthomode transducer device is established, as each of the orthomode transducers is assigned to a certain frequency band. 
     For instance, the separate frequency bands together range from 20 to 90 GHz. A first frequency band may range from 20 to 40 GHz, a second frequency band may range from 40 to 60 GHz and a third frequency band may range from 60 to 90 GHz. Hence three orthomode transducers are provided, which are assigned to the respective frequency bands. 
     Another aspect provides that at least one of the rotary positioner, a multiplexer and a switch is provided. Hence, the entire multi-band orthomode transducer device with the integrated orthomode transducers may be rotated to cover the different frequency bands. 
     Further, a multiplexer, particularly a waveguide multiplexer, and/or a switch may be provided in order to switch to and fro the respective orthomode transducers, particularly the respective waveguides of the orthomode transducers. Hence, it can be ensured that only one of the several orthomode transducers is active while the others are deactivated. 
     Another aspect provides that an antenna is connected to each of the third ports. Hence, signals may be received via the respective antenna connected to the third port of each orthomode transducer. Alternatively, signals may be transmitted via the respective antenna wherein the signals are based on signals fed into the respective first and second ports of each orthomode transducer. 
     For instance, the respective antenna is a horn antenna. The horn antenna is a dual-polarized antenna ensuring to emit signals with two different polarizations, namely orthogonal polarizations. 
     Generally, the multi-band orthomode transducer device may be single-housed. This means that the several orthomode transducers of the multi-band orthomode transducer device are encompassed within the single three-dimensional housing. Thus, moving or rather rotating the multi-band orthomode transducer device results in a respective movement or rather rotation of the integrated orthomode transducers. The single-housed orthomode transducer device is a single unit. 
     The three-dimensional housing may have a polygonal shape, a cylindrical shape or a spherical shape. The polygonal shape might relate to a three-dimensional body having a square base area, a pentagon base area or a hexagon base area. Depending on the number of orthomode transducers integrated in the multi-band orthomode transducer device, the housing may have a certain shape. 
     Generally, the respective ports are located at the outer surface(s) of the three-dimensional housing. The waveguides of the orthomode transducers are fully integrated in the housing, wherein the waveguides are connected with the corresponding ports positioned at the outer surface(s) of the housing. 
     According to an embodiment, the multi-band orthomode transducer device comprises three orthomode transducers integrated in the three-dimensional housing, each orthomode transducer having three different ports, namely a first port, a second port and a third port. 
     The base area and/or the top area may relate to a flat outer surface of the housing. 
     The first and second ports of each orthomode transducer may be located in recesses of the respective side, for instance the lateral side. The recesses may extend over the entire side, namely the lateral side. Hence, the recesses reach from the top area to the base area. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of the claimed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  shows a multi-band orthomode transducer device according to the present disclosure, and 
         FIG. 2  shows a multi-band orthomode transducer device of  FIG. 1  in a partly transparent manner. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings, where like numerals reference like elements, is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed. 
       FIG. 1  shows schematically a multi-band orthomode transducer device  10  that has a three-dimensional housing  12  with a cylindrical shape. Thus, the housing  12  comprises a substantially disk-shaped base area  14  as well as a substantially disk-shaped top area  16  that is opposite to the base area  14 . The base area  14  and the top area  16  are parallel with respect to each other. 
     Further, the base area  14  and the top area  16  are connected with each other by a lateral surface  18 , namely a circular shaped lateral surface, that is perpendicular to the base area  14  as well as the top area  16 . 
     In the shown embodiment, the multi-band orthomode transducer device  10  comprises three orthomode transducers  20 ,  22 ,  24  that are integrated in the common three-dimensional housing  12 . 
     Each of the orthomode transducers  20  to  24  comprise a respective first port  26 ,  28 ,  30 , which can be used as a respective first output port of the respective orthomode transducer  20  to  24 . Further, each of the orthomode transducers  20  to  24  comprises a second port  32 ,  34 ,  36 , which can be used as a second output port of the respective orthomode transducer  20  to  24 . 
     Besides the first and second ports  26  to  36 , each of the orthomode transducers  20  to  24  comprises a third port  38 ,  40 ,  42 , which can be used as a feed port of the respective orthomode transducers  20  to  24 . 
     Accordingly, signals may be received via the third ports  38  to  42  which are processed by the respective orthomode transducers  20  to  24  resulting in differently polarized signals or rather signal portions, also called component signals, forwarded to the first and second ports  26  to  36  of the respective orthomode transducers  20  to  24 . Hence, the signal received may be split with respect to its polarization components. 
     Alternatively, signals are fed to the first and second ports  26  to  36  of the respective orthomode transducers  20  to  24 , which are combined to a combined signal outputted via the respective third port  38  to  42  of the orthomode transducers  20  to  24 . Accordingly, the third ports  38  to  42  may be used as output port, whereas the first and second ports  26  to  36  relate to feed ports. 
     As shown in  FIGS. 1 and 2 , the first ports  26  to  30  of each orthomode transducer  20  to  24  are located opposite to the respective third ports  38  to  42 . 
     Further, the first ports  26  to  30  are located in different planes E 1 , E 2 , E 3  which are parallel to the base area  14  or rather the top area  16 . In other words, the first ports  26  to  30  of the orthomode transducer  20  to  24  are positioned at different heights. 
     Since the first ports  26  to  30  of each orthomode transducer  20  to  24  are located opposite to the respective third ports  38  to  42 , the third ports  38  to  42  are also located in the different planes E 1 , E 2 , E 3 . In other words, the first ports  26  to  30  and the third ports  38  to  42  of the respective orthomode transducer  20  to  24  are located in a common plane. 
     The first ports  26  to  30  as well as the third ports  38  to  42  are located at the lateral surface  18 , whereas the second ports  32  to  36  of each orthomode transducer  20  to  24  are located at the top area  16 , namely at a common side of the three-dimensional housing  12 , which is assigned to the top of the housing  12 . In other words, the second ports  32  to  36  are located in a common plane that is parallel to the base area  14  since the top area  16  is parallel to the base area  14 . 
     Further, the first ports  26  to  30  are orientated perpendicularly with respect to the second ports  32  to  36 , as the lateral surface  18  is perpendicular to the top area  16 . 
     With reference to  FIG. 2 , it becomes obvious that the respective ports  26  to  42  of each orthomode transducer  20  to  24  are assigned to a respective waveguide  44 ,  46 ,  48  of the orthomode transducers  20  to  24 . The respective waveguides  44  to  48  of the orthomode transducers  20  to  24  do not intersect with each other within the three-dimensional housing  12 . Thus, the signals processed by the orthomode transducers  20  to  24  are separated from each other. In other words, the several orthomode transducers  20  to  24  are not connected to a same antenna and, thus, sharing a common signal received, as they are assigned to dedicated antennas used for respective antenna bands. 
     The specific arrangement can be ensured in an easy manner, as the respective first ports  26  to  30  as well as the third ports  38  to  42  are located in different planes E 1  to E 3 , namely at different heights. 
     The respective waveguide  44  to  48  of each orthomode transducer  20  to  24  connects the respective first port  26  to  30  with the respective third port  38  to  42  in a straight manner, as the first ports  26  to  30  are located opposite to the third ports  38  to  42 . 
     In addition, the second ports  32  to  36  of each orthomode transducer  20  to  24  are also connected to the respective waveguides  44  to  48 . 
     The waveguides  44  to  48  of each orthomode transducer  20  to  24  are located at different heights with respect to the base area  14 . This can be verified easily in a side view on the multi-band orthomode transducer device  10 . 
     Hence, the waveguides  44  to  48  are arranged in the respective planes E 1  to E 3 , in which the respective first ports  26  to  30  as well as the respective third ports  38  to  42  are also located. 
     Further, each of the orthomode transducers  20  to  24  comprises an antenna  50 ,  52 ,  54 . The antennas  50  to  54  are connected with the third ports  38  to  42  of the respective orthomode transducers  20  to  24 . In the shown embodiments, the antennas  50  to  54  are established as horn antennas. 
     Accordingly, the third ports  38  to  42  of each orthomode transducer  20  to  24  are shaped circularly, whereas the output ports  26  to  36  are shaped rectangularly. 
     As the antennas  50  to  54  are connected with the third ports  38  to  42 , the antennas  50  to  54  are also located at different heights with respect to the base area  14 . 
     Thus, the multi-band orthomode transducer device  10  comprises an integrated rectangular to circular transition  56  for each orthomode transducer  20  to  24 . In other words, three integrated rectangular to circular transitions  56  are provided. For instance, the respective transitions  56  are established by the respective waveguides  44  to  48 . 
     As already indicated in the Figures, each of the orthomode transducers  20  to  24  is assigned to a separate frequency band establishing the multi-band orthomode transducer device  10 . 
     The separate frequency bands processed by the multi-band orthomode transducer device  10  together range from 20 to 90 GHz. Hence, the first orthomode transducer  20  may be assigned to a first frequency band (band  1 ) that ranges from 20 to 40 GHz, wherein the second orthomode transducer  22  may be assigned to a second frequency band (band  2 ) that ranges from 40 to 60 GHz, and wherein the third orthomode transducer  24  is assigned to a third frequency band (band  3 ) that ranges from 60 to 90 GHz. 
     In operation of the multi-band orthomode transducer device  10 , the housing  12  and, thus, the integrated orthomode transducers  20  to  24  may be rotated by a rotary positioner  58  that is assigned to the housing  12 , as shown in  FIGS. 1 and 2 . 
     As discussed above, the multi-band orthomode transducer device  10  may receive signals via the respective antennas  50  to  54  wherein each of the antenna  50  to  54  is assigned to a certain frequency band, namely the first frequency band, the second frequency band as well as the third frequency band as described above. 
     The orthomode transducers  20  to  24  split the signals received for each of the separate frequency bands into different polarized signals or rather signal portions, particularly orthogonally polarized signals or rather signal portions, which are forwarded to the respective first and second ports  26  to  36 . The first and second ports  26  to  36  may be connected with waveguides for feeding a network assigned to the waveguides. 
     Alternatively, the network may provide different polarized, particularly orthogonally polarized, signals or rather signal portions, which are fed via the first and second ports  26  to  36 . The signals or rather signal portions are forwarded to the orthomode transducers  20  to  24  that combine the signals or rather signal portions to a combined signal outputted via the respective third ports  38  to  42 , particularly the antennas  50  to  54  connected with the third ports  38  to  42 . 
     Generally, a multiplexer and/or a switch may be assigned to the multi-band orthomode transducer device  10  such that the respective orthomode transducer  20  to  24  may be activated or deactivated for measuring purposes. 
     Accordingly, a single-housed multi-band orthomode transducer device  10  is provided that can be used in an easy and efficient manner for measuring high bandwidth, as several orthomode transducers  20  to  24  are integrated in a common three-dimensional housing  12  of the multi-band orthomode transducer  10 . The several orthomode transducers  20  to  24  are rotated commonly when the housing  12  is rotated by means of the rotary positioner  58 . 
     In addition, the multi-band orthomode transducer device  10  may be used in a testing system, for instance a Compact Antenna Test Range (CATR) system or rather a Wireless Performance Testing Chamber (WPTC) system. However, the multi-band orthomode transducer device  10  may also be used in far-field testing systems. 
     The testing system may relate to testing separate frequency bands from 20 to 90 GHz for 5G Frequency Range 2 (FR2) and spurious emissions. 
     Hence, an over-the-air (OTA) testing system may comprise the multi-band orthomode transducer device  10  for simplifying testing communication devices with regard to wideband signals, as the multi-band orthomode transducer device  10  ensures processing several separate frequency bands.