Patent Publication Number: US-6906679-B2

Title: Light weight portable phased array antenna

Description:
TECHNICAL FIELD 
     This invention relates generally to an antenna system and in particular to a light weight portable phased array antenna system for receiving high bandwidth signals from satellites. 
     BACKGROUND 
     Although antenna systems that use light communication channels in combination with phased array antenna elements have already been implemented, thus far none of these antenna systems have been adapted to form a portable lightweight collapsible unit. Such a configuration is desirable to provide convenient and portable access to movies on demand or internet service for campers, hikers, travelers and others who may find themselves in remote areas where other communication connections are not readily available. The antenna system of the present invention is easily assembled and disassembled and compact for transporting. 
     SUMMARY 
     The present invention provides an antenna system for receiving communication signals from satellites, the antenna system having a plate of light channel material that is formed from a plurality of subplates, a plurality of antenna nodes supported on the top surface of each of the subplates, and an electronic control unit to which the subplates are fixed and aligned and a collapsible support stand fixed to the bottom of the electronic control unit opposite the subplates, the subplates, antenna nodes, electronic control unit and stand interconnecting to form a lightweight antenna assembly that may be disassembled into easily portable components. 
     These and other aspects and advantages of the present invention will become apparent upon reading the following detailed description of the invention in combination with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a three dimensional graphic representation of a portable light weight phased array antenna assembly; 
         FIG. 2  is a three dimensional exploded view of the antenna assembly showing the electronic control unit and the LCC subplates; 
         FIG. 3  is an exploded top view of the phased array showing the metal conductors or traces that connect the antenna nodes and the electronic control unit; 
         FIG. 4  is an exploded bottom view of the antenna assembly showing the alignment features for the LCC subplates; 
         FIG. 5  is an exploded view of the collapsible support stand and the electronic control unit with a partial view of two of the subplates; 
         FIG. 6  is a partial cross-sectional view of a subplate taken along section arrows  6 — 6  of FIG.  5 . 
         FIG. 7  is a functional block diagram depicting the operation of one of the antenna&#39;s nodes in receiving mode. 
         FIG. 8  is a functional block diagram depicting the operation of one of the antenna&#39;s nodes in transmitting mode. 
     
    
    
     DETAILED DESCRIPTION 
     The following description of the preferred embodiments of the inventive system is not intended to limit the inventive system to these preferred embodiments, but rather to enable any person skilled in the art of phased array antenna systems to make and use the inventive system. 
     Referring to  FIG. 1 , the light weight portable phased array antenna assembly or antenna system  10  for receiving high band width signals from satellites is shown fully assembled and standing upright on its collapsible support stand  20 . The preferred embodiment of the antenna system  10  includes a plurality of small dipole antenna elements or antenna nodes  30  that form a phased array  40  for transmitting and receiving signals. Each of the antenna nodes  30  of the phased array  40  is located and supported in a fixed and certain position on a plate  46  of light channel communication (LCC) substrate material. 
     As shown in  FIG. 2 , the LCC substrate plate  46  in the preferred embodiment is actually made up of four subplates  50   a  through  50   d,  each comprised of LCC substrate material. The LCC substrate plate  46 , however, could be made by one skilled in the art using any number of subplates  50 . 
     The LCC substrate plate  46  is detachably fixed to the collapsible support stand  20 . The combination of the LCC substrate plate  46  and the detachable and collapsible support stand  20  allows the antenna system  10  to be easily assembled and disassembled into a compact unit for ease in transport. The construction of the LCC substrate plate  46  from the four subplates  50   a  through  50   d  further facilitates the easy transport of the antenna system  10 . 
     Each of the plurality of antenna nodes  30  communicates through one of the LCC subplates  50   a  through  50   d  with a central processor or electronic control unit  60  that combines the incoming signals, calculates deviations among the signals due to differences in the location and direction of the antenna nodes, and sends control signals back to the antenna nodes  30  that allow the timing or delay of some or all of the antenna nodes  30  to be adjusted relative to the others to obtain a synchronized condition among the antenna nodes  30 , thus allowing them to process signals in which the phase is synchronized. Use of light channel technology to form the substrate subplates  50   a  through  50   d  makes the preferred embodiment of the inventive antenna system  10  light weight and portable. 
     The material making up the subplates plates  50   a  through  50   d  in the preferred embodiment is a light-weight light channel communication (LCC) substrate material such as polycarbonate, PETG (glycolized polyester—polyethylene terephtalate with glycol modifiers) or acrylic (polymethyl methacrylate), but its functionality could easily be accomplished through the use of any other strong and light-weight material that is a good conductor of light. The LCC substrate material making up the subplates  50   a  through  50   d  channels or conveys the signal information from each of the antenna nodes  30  to the electronic control unit  60  for data processing. Using the LCC substrate material to comprise the subplates  50   a  through  50   d  eliminates the need for circuit boards or wiring harnesses that can often be large, heavy and bulky. 
     As seen in  FIG. 3 , the LCC substrate material forming the plate  46  and its comprising subplates  50   a  through  50   d  also supports metal conductors or traces  70 . The metal conductors or traces are routed to each of the antenna nodes  30  to provide transmission pathways for power. The conductors  70  may be implemented as printed conductive polymer, electroplated traces, flat wire or flexible circuit material that is bonded directly to the LCC material of the subplates  50 , or in any of the other ways that are well known to one skilled in the art of antenna systems. 
     As shown in FIG.  2  and  FIG. 4 , the four separate substrate plates  50   a  through  50   d  of the preferred embodiment are each aligned with and connected to the housing of the electronic control unit  60  to form the complete substrate plate  46  and phased array  40 . The alignment features  92  on the back of each subplate  50   a  through  50   d  position and aid in securing each of the subplates  50   a  through  50   d  to the housing of the electronic control unit  60 . Each of the alignment features  92  mates with a subplate alignment hole  93  on the housing of the electronic control unit  60  to mechanically align the subplates  50   a  through  50   d.    
     Referring now to FIG.  5  and FIG  6 , each of the antenna nodes  30  communicates with the main electronic control unit  60  through the optically transparent plate  46 . Power is supplied by means of conductive traces or conductors  70  that are routed from each of the antenna nodes  30  to an interconnect pad  71 . Each of the interconnect pads  71  is connected to a duplicate interconnect pad  72  on the under side of the LCC subplate  50   a  through  50   d  by means of a copper plated through hole  73 . The duplicate interconnect pacts  72  are in turn each connected to one of a plurality of conductor pads  80  embedded in the housing of the electronic control unit  60  using any one of the many known methods of interconnection, such as by way of example, connectors or press fit pins, thereby completing a communications path from each of the antenna nodes  30  to the electronic control unit  60  that processes the signal data. The electronic control unit  60  is located and secured to the collapsible support stand  20  through means of a central locator pin  94  that mates with a central alignment hole  95  in the housing of the electronic control unit  60   
     Also shown in FIG  5  is an emitter/transmitter LED  90  that transmits signals from the electronic control unit  60  to the plurality of antenna nodes  30  that form the phased array  40 . Conversely, photoreceptors or other receiver devices  91  receive signals from the plurality of antenna nodes  30  in the phased array  40  and convey these signals to the electronic control unit  60 . 
     The node electronics  100 ,  101  shown in FIG.  7  and  FIG. 8  are provided for each of the antenna nodes  30  in the phased array  40 . The node electronics  100 ,  101  functionally support the transmitting and receiving functions of its respective antenna node  30  and are preferably contained in the respective antenna node  30 , but alternatively could be attached on, to or near a corresponding conductor  70  on the LCC subplates  50 . 
     Referring now to  FIG. 7 , each of the receiving node electronics  100  consists of a dipole element  110  attached to a low noise amplifier  120 , which in turn feeds a programmable phase delay element  130 . The output of the phase delay element  130  modules the output of a light emitting or laser diode  140  that is coupled to the LCC material of the subplate  50 . The light is gathered and combined at the receiver devices  91 , which couple the signal to detector/demodulation circuits within the electronic control unit  60 . The electronic control unit  60  processes the signal to produce the resultant broadband signal. 
     A local processor  170  within the receiving node electronics  100  receives signals from the electronics control unit  60  via a pin  160  within the receiving node electronics  100 . The local processor  170  calculates the appropriate delays for the dipole element  110  and modulates an LED/transceiver to send that information back to the appropriate antenna nodes  30  in the phased array  40  in order to adjust the delay of each of the antenna nodes  30  as needed to achieve synchronization of the phased array  40 . The adjustment in the delay of the antenna nodes  30  is controlled by microprocessor controlled phase delay lines contained in the electronic control unit  60 . 
     Referring to  FIG. 6 , the transmit function of the node electronics  101  is shown to operate in manner that is similar to the receiving function of the node electronics  100  depicted in FIG.  5 . The main electronic control unit  60  sends signals via the LCC subplates  50  to each of the antenna nodes  30  providing the delay information to point the antenna system&#39;s  10  substrate plate  46  and phased array  40  in the correct direction. The transmit signal is also conveyed to a transmit antenna node  30  where it is delayed, amplified and conducted to the dipole element. 
     The preceding description of the preferred embodiments of the inventive system is not intended to limit the inventive system to these preferred embodiments, but rather to enable any person skilled in the art of phased array antenna systems to make and use this invention. As any person skilled in the art of phased array antenna systems will recognize from the previous detailed description and from the figures and claims, modifications and changes could be made to the preferred embodiments of the inventive system without departing from the scope of this invention system defined in the following claims.