Abstract:
A transceiver allowing transmission of a co-polar transmit signal and simultaneous reception of co-polar receive and cross-polar receive signals. An integrated orthogonal mode transducer and diplexer module containing a plurality of filters between a feed port, co-polar transmission port, co-polar reception port and cross-polar reception port is mounted within the transceiver housing with the feed port aligned with or forming the feed flange of the transceiver. A transmitter printed circuit board is aligned with the transmission waveguide port and a receiver printed circuit board is aligned with the co-polar reception and cross-polar reception ports of the integrated orthomode transducer and diplexer module.

Description:
BACKGROUND 
     Satellite communication systems are known and generally well understood. Integrated transceivers proximate the boom arm of a satellite dish directly link the antenna feed to signal separation, reception and transmission components and electrical circuitry housed within a common enclosure, greatly simplifying component interconnections and environmental sealing requirements. 
     Satellite communications radio frequency signals may be received and or transmitted via cross-polar or co-polar signals. Filtering required to separate these signals from one another has previously required numerous separate filter components resulting in an assembly that is unacceptably large and or has degraded electrical performance. Previous systems have used an integrated transceiver or separate transmit electronics, receive electronics and an orthomode transducer (OMT) or diplexer to receive co-polar or cross-polar signals with respect to the transmission signal. 
     The increasing competition for integrated satellite transceivers adapted for high volume consumer applications has focused attention on improving electrical performance as well as cost reductions resulting from reduced materials and manufacturing cost as well as service and installation efficiencies. 
     Therefore, it is an object of the invention to provide an apparatus that overcomes deficiencies in the prior art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general and detailed descriptions of the invention appearing herein, serve to explain the principles of the invention. 
         FIG. 1  is an isometric front side view of an exemplary embodiment of the invention. 
         FIG. 2  is an isometric end view of an exemplary embodiment of the invention. 
         FIG. 3  is a cut-away side view of  FIG. 1 . 
         FIG. 4  is an isometric view of a two portion OMT and diplexer module according to the invention, showing the interior surfaces of the two portions. 
         FIG. 5  is an isometric exploded view of the housing and OMT/diplexer, showing mounting surfaces for the OMT and diplexer module within the receiver cavity of the housing. 
     
    
    
     DETAILED DESCRIPTION 
     A transceiver with a cross-polar, co-polar receiver according to the invention is integrated into a single enclosure  10 . An OMT and diplexer module  12  may be mounted within the transceiver enclosure  10  without requiring specialized alignment procedures in multiple planes. 
     As shown in  FIGS. 1-3  an enclosure  10  according to an exemplary embodiment of the invention has a feed flange  14  connection on a front end  16  and signal connection(s)  17  at the back end  18 . The enclosure has a top side transmitter cavity  20  and a bottom side receiver cavity  22 . A receiver cavity cover  24  and a transmitter cavity cover  26  enclose and environmentally seal the receiver cavity  22  and the transmitter cavity  20 , respectively. Heat sink(s)  28  may be arranged along the exterior sides of the enclosure  10  to assist with dissipation of heat generated by transceiver operation. 
     The OMT and diplexer module  12 , as best shown in  FIG. 4 , may be formed as a two piece assembly with grooves and sealing surfaces that cooperate to form a waveguide  30  and filter network functioning as an OMT and diplexer with cross-polar transmit reject filter (X-TRF)  32 , co-polar transmit reject filter (C-TRF)  34 , and co-polar receive reject filter (C-RRF)  36 . Signals are routed along a range of different waveguide  30  paths between a feed port  38 , co-polar transmission port  40 , co-polar reception port  42  and cross-polar reception port  44 . Arrayed along the different paths, the X-TRF  32 , C-TRF  34  and C-RRF  36  filters are formed in the waveguide  30  sidewalls and or by application of a selected waveguide  30  cross section dimension relative to other waveguide  30  paths to remove undesired radio frequency signal components. Design and dimensional specifics of waveguide band-pass, high-pass and notch filters are well known in the art and as such are not discussed herein with greater detail. 
     As shown in  FIG. 5 , the floor of the receiver cavity  22  may be adapted to receive the OMT and diplexer module  12 . The OMT and diplexer module  12  is coupled to the feed flange  14  and is aligned with the enclosure  10  via a plurality of fasteners such as screws or like. The receiver printed circuit board  46  below and transmitter printed circuit board(s)  48  above are also thereby aligned to the other OMT and diplexer module  12  ports. Alternatively, a variety of snap on or interference fit connections may be applied. Also, the OMT and diplexer module  12  may be alternatively located in the transmitter cavity  20 . The OMT and diplexer module  12  feed port  38  itself may form the feed flange  14  of the transceiver or alternatively the feed port  38  may be aligned directly with the feed flange  14  of the transceiver. Thereby avoiding the need for precision alignment between the OMT and diplexer module  12  to the enclosure  10  at the additional plane of the feed location. 
     The OMT and diplexer module  12  cross-polar reception port  40  and co-polar reception port  42  may be arranged to exit the OMT and diplexer module  12  on a common side, while the co-polar transmission port  44  exits on an opposite side to couple with the receiver printed circuit board  46  and transmitter printed circuit board(s)  48 , respectively. The receiver printed circuit board  46  and the transmitter printed circuit board(s)  48  may be enclosed within the receiver cavity  22  and the transmitter cavity  20  by the receiver cavity cover  24  and the transmitter cavity cover  26  or other form of radio frequency and environmental screen. Positioning of the receiver printed circuit board  46  and the transmitter printed circuit board(s)  48  within separate reception and transmission cavities  22 ,  20  of the enclosure  10  isolates the electrical circuitry for transmission and reception from each other. This helps to reduce cross coupling between different circuits on the receiver and transmitter printed circuit boards  46 ,  48 . 
     The planar two piece design of the OMT and diplexer module  12  enables use of cost efficient manufacturing methods such as die casting or injection molding. The X-TRF  32 , C-TRF  34  and C-RRF  36  are seamlessly incorporated into the OMT and diplexer module  12 , eliminating additional interconnections and potential signal degradation. The filters enable reception of signals in both orthogonal polarities while transmitting in one polarity. The OMT and diplexer module  12  may be fully tested prior to mounting in the enclosure  10 ; improving yield at transceiver final assembly and simplifying quality control procedures. Similarly, the enclosure  10  may be cost effectively manufactured with a high level of precision via die casting or injection molding. Cavities, ports, fastener points, alignment posts and any heat sinks may be configured for die/mold separation without interfering overhanging edges. Where injection molding is performed, a plastic material with enhanced thermal conductivity properties may be used and or the surfaces of the resulting components may be coated with a conductive material to prevent radio frequency interference or leakage. Further, to enhance heat dissipation characteristics, metal inserts may be placed within the molds before injection of the plastic material to form integral heat sinks within the molded OMT and diplexer module  12  portion(s). 
     One skilled in the art will appreciate that the present invention significantly improves both electrical functionality and cost efficiency. Further, the modular design enables rapid application of further mechanical and or electrical circuit improvements that may arise. Because the number of required interconnections has been reduced, a transceiver according to the invention may be smaller and lighter than previous assemblies of similar function. 
     TABLE OF PARTS 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 10 
                 enclosure 
               
               
                 12 
                 OMT and diplexer module 
               
               
                 14 
                 feed flange 
               
               
                 16 
                 front end 
               
               
                 17 
                 signal connection 
               
               
                 18 
                 back end 
               
               
                 20 
                 transmitter cavity 
               
               
                 22 
                 receiver cavity 
               
               
                 24 
                 receiver cavity cover 
               
               
                 26 
                 transmitter cavity cover 
               
               
                 28 
                 heat sink 
               
               
                 30 
                 waveguide 
               
               
                 32 
                 cross-polar transmit reject filter 
               
               
                 34 
                 co-polar transmit reject filter 
               
               
                 36 
                 co-polar receive reject filter 
               
               
                 38 
                 feed port 
               
               
                 40 
                 co-polar transmission port 
               
               
                 42 
                 co-polar reception port 
               
               
                 44 
                 cross-polar reception port 
               
               
                 46 
                 receiver printed circuit board 
               
               
                 48 
                 transmitter printed circuit board 
               
               
                   
               
             
          
         
       
     
     Where in the foregoing description reference has been made to ratios, integers, components or modules having known equivalents then such equivalents are herein incorporated as if individually set forth. 
     While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus, methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of applicant&#39;s general inventive concept. Further, it is to be appreciated that improvements and/or modifications may be made thereto without departing from the scope or spirit of the present invention as defined by the following claims.