Abstract:
A passive directional coupler is receptive of VoIP, Internet, and video/data signals, and is used in a CATV amplifier device to couple the video/data signals to the input terminal of an amplifier, and to bypass the VoIP and Internet signals to a modem port, for insuring continuous connection of the VoIP and Internet signals to the a modem of a user connected to the modem port, regardless of the loss of power to the amplifier or the failure of the amplifier.

Description:
RELATED APPLICATION  
       [0001]     The present invention is related to and takes priority from co-pending Provisional Ser. No. 60/726,574, filed on Oct. 14, 2005, the teachings of which are incorporated herein by reference to the extent they do not conflict herewith. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to amplifiers, and more specifically to amplifiers for use in cable television systems.  
       BACKGROUND OF THE INVENTION  
       [0003]     A problem in present amplifiers used in cable television systems is that when there is a power outage or an amplifier otherwise becomes inoperative, the home or business user loses use of their cable modem for Internet communications. As a result, the home user will lose the use of VoIP (voice over internet protocol), and other access to the Internet. To avoid this problem bypass switching or switches have been installed in CATV systems to switch the feed cable or cable drop from the input of the amplifier directly to the input/output port of the modem. Also, relays have been used to accomplish this purpose when the amplifier loses power. There is a need in the art to improve upon present methods to maintain a home or business user&#39;s connection between their modem and the Internet in the event of an associated amplifier losing power or becoming defective.  
       SUMMARY OF THE INVENTION  
       [0004]     In one embodiment of the invention a directional coupler is built into a CATV amplifier to receive a cable drop or feed providing video/data, VoIP, and other connection to the Internet, and to couple the VoIP signals and unamplified video/data signals directly to a passive output port for connection to the modem of the user, and further couple the video/data signals to the input of the amplifier. The output of the amplifier is connected directly to a video/data active output port for one embodiment of the invention, or via a splitter to a plurality of video/data active output ports for other embodiments of the invention, for providing amplified video/data signals. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]     Various embodiments of the invention are described below with reference to the drawings, in which like elements are identified by the same reference designation, wherein:  
         [0006]      FIG. 1A  is a pictorial view of a one-output amplifier housing for one embodiment of the invention;  
         [0007]      FIG. 1B  is a block and electrical schematic diagram of the amplifier of  FIG. 1A ;  
         [0008]      FIG. 2A  is a pictorial view of a three-output amplifier housing for a second embodiment of the invention;  
         [0009]      FIG. 2B  is a block and electrical schematic diagram of the amplifier of  FIG. 2A ;  
         [0010]      FIG. 3A  is a pictorial view of an eight output amplifier housing for a third embodiment of the invention; and  
         [0011]      FIG. 3B  is a block and electrical schematic diagram of the amplifier of  FIG. 3A . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     In  FIG. 1A  a one-output amplifier  1  having a housing  3  is shown for one embodiment of the invention. With reference to  FIGS. 1A and 1B , the amplifier  1  includes an input port  5  for connection to a cable drop  6  or coaxial cable carrying video/data signals, VoIP, and Internet connection signals. Internally, the port  5  is electrically connected to a passive directional coupler  7  which partially bypasses a forward/reverse amplifier  9 , and delivers or connects primary data services signals (Internet, VoIP, etc., at 2 dB down, in this example) directly to a passive modem port  19 , along with unamplified video/data signals. In this manner, if there is a power interruption to the amplifier  9  or a failure in the amplifier  9  itself, there will no interruption in the primary data service connection to the modem  20  of the home or business user. In this unique manner, compliance with e911 is provided. Directional coupler  7  also delivers or connects the video/data signals to an input of amplifier  9  (at −6 dB down, in this example). A power port  11  provides for connection to a DC voltage source  12 , +12 VDC, in this example. A diode  13  is connected between the port  11  and the amplifier  9 , and is polarized for passing the DC voltage to a power input terminal  10  of amplifier  9 . Modem port  19  is connected through an inductor  17  for blocking high frequency signals in series with a diode  15  polarized for passing a positive DC voltage to amplifier  9 , if power is to be provided thereto via a power inserter connected to modem port  19  rather than by connection of a source of positive DC voltage  12  to power port  11 . In this embodiment, the output of amplifier  9  is connected directly to a single active output port  21  for delivering amplified video/data signals  22  to a user.  
         [0013]     In  FIG. 2A  a three output amplifier device  23  having a housing  25  is shown for a second embodiment of the invention. With reference to  FIGS. 2A and 2B , the amplifier device  23  includes an input port  27  for connection to a cable drop  28  or coaxial cable carrying video/data signals, and Internet connection signals. Internally, the port  27  is electrically connected to a passive directional coupler  29  which partially bypasses a forward/reverse amplifier  31 , and delivers or connects primary data services (Internet, VoIP, etc., at −2 dB down, in this example) and unamplified video/data signals directly to a passive modem port  41 . In this manner, if there is a power interruption to the amplifier  31  or a failure in the amplifier  31  itself, there will no interruption in the primary data service connection to the modem  42  of the home or business user. In this unique manner, compliance with e911 is provided. Directional coupler  29  also delivers or connects the video/data signals to an input of amplifier  31  (at −6 dB down, in this example). A power port  33  provides for connection to a DC voltage source  34 , +12 VDC, in this example. A diode  35  is connected between the port  33  and the amplifier  31 , and is polarized for passing the DC voltage to amplifier  31 . Modem port  41  is connected through an inductor  39  for blocking high frequency signals in series with a diode  37  polarized for passing a positive DC voltage to amplifier  31 , if power is to be provided thereto via a power inserter connected to modem port  41  rather than by connection of a source of positive DC voltage  34  to power port  33 . In this embodiment, the output of amplifier  31  is connected via a splitter  43  to three active video/data output ports  45 ,  47 , and  49 , for delivering amplified video/data signals thereto. Note that the splitter  43  is a passive device.  
         [0014]     In  FIG. 3A  an eight output amplifier device  51  having a housing  53  is shown for a third embodiment of the invention. With reference to  FIGS. 3A and 3B , the amplifier device  51  includes an input port  81  for connection to a cable drop  82  or coaxial cable carrying video/data signals, VoIP and Internet connection signals. Internally, the port  81  is electrically connected to a passive directional coupler  57  which partially bypasses a forward/reverse amplifier  65 , and delivers or connects primary data services (Internet, VoIP, etc., at −3.5 dB down, in this example) and unamplified video/data signals directly to a passive modem port  55 . In this manner, if there is a power interruption to the amplifier  65  or a failure in the amplifier  65  itself, there will no interruption in the primary data service connection to the modem  56  of the home or business user. In this unique manner, compliance with e911 is provided. Directional coupler  57  also delivers or connects the video/data signals to an input of amplifier  65  (at −3.5 dB down, in this example). A combined video/data output and power input port  59  provides for connection to a DC voltage source  60 , +12 VDC, in this example. This video/data output and power input port  59  is connected through an inductor  61  for blocking high frequency signals in series with a diode  63  polarized for passing a positive DC voltage to amplifier  65 , thereby permitting power to be provided thereto via either a power inserter or by a source  60  of positive DC voltage connected to power port  59 . In this embodiment, the output of amplifier  65  is connected via a splitter  66  to eight video/data output ports  59 ,  67 ,  69 ,  71 ,  73 ,  75 ,  77 , and  79 , for providing amplified video/data signals  62 ,  68 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 , and  82  thereto, respectively. Note that the splitter  66  is a passive device.  
         [0015]     In engineering prototypes for the embodiment of the invention for  FIGS. 1A and 1B , for  FIGS. 2A and 2B , and for  FIGS. 3A and 3B , respectively, unity gain in both the forward and reverse signal directions through the respective amplifiers  9 ,  31 , and  65  is provided to maintain drop symmetry. Also, in the embodiment of the invention of  FIG. 3A , mounting tabs  84  are provided at the corners indicated, for permitting vertical or horizontal mounting of the housing  53  of the eight output amplifier device  51 . Also, in each of the aforesaid embodiments of the invention, low power integrated circuits (ICs) were utilized in order to provide a small footprint, and to reduce or minimize cooling requirements. Also, through use of surface-mount components, the associated size of the housings required were minimized, and also provided for close control of the related electrical impedances and electrical isolation, for providing a linear frequency response in either forward or reverse signal directions, respectively.  
         [0016]     Although various embodiments of the invention have been shown and described, they are not meant to be limiting. Those of skill in the art may recognize certain modifications to the invention as taught, which modifications are meant to be covered by the spirit and scope of the appended claims. For example, in certain applications, the directional couplers can be replaced by splitters.