Patent Publication Number: US-2010117728-A1

Title: Signal Amplifiers Having Communications Paths that Automatically Terminate to a Matched Termination in Response to a Power Interruption and Related Methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §120 as a continuation-in-part application of U.S. patent application Ser. No. 12/208,675, filed Sep. 11, 2008, which in turn claims priority under 35 U.S.C. §120 as a continuation-in-part application of U.S. patent application Ser. No. 11/077,802, filed Mar. 10, 2005. This application further claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application Ser. No. 61/175,191, filed May 4, 2009. The disclosure of each of the above applications is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to technology for providing non-interruptible communication. 
     BACKGROUND 
     In recent years, the rise of the Internet and other online communication methods have rapidly transformed the manner in which electronic communications take place. Today, rather than relying on prior-generation switched telephone communication arrangements, many service providers are turning to modern Internet Protocol (IP) based communication networks. Such networks can provide flexibility in facilitating the transmission of voice, data, video, and other information at great speeds. 
     As a result, many consumers now have the option of conducting telephone conversations, receiving and sending information for interactive video, and communicating over the Internet—all through a single RF connection with the consumer&#39;s service provider. However, in order to support these various services, the RF signal received from the service provider (approximately 5 dBmV/channel) may require amplification by an RF amplifier in order to properly service the various communication ports maintained by a consumer. 
     Unfortunately, if power to the RF amplifier is interrupted, some or all of these services may become unavailable. Although such interruptions may be tolerated by consumers in relation to certain non-essential services, interruptions to other services may be unacceptable. For example, consumers relying on IP-based emergency communications (i.e., 911 service) can be left without such services during power interruptions. 
     In order to remedy this problem, some consumers may be inclined to acquire a dedicated switched telephone line to provide emergency services during power interruptions. Nevertheless, such an option can require the consumer to incur additional costs and fails to capitalize on the advantages offered by IP-based communication. 
     SUMMARY 
     Pursuant to embodiments of the present invention, bi-directional RF signal amplifiers are provided that include an RF input port, a first RF output port, a second RF output port and a power input for receiving electrical power. The second RF output port may be a voice-over-IP RF output port. These amplifiers further include a directional coupler having an input that is coupled to the RF input port, a first output and a second output. The second output of the directional coupler is connected to the second RF output port via a non-interruptible communication path. A first switching device having an input, a first output and a second output is also provided. The second output of the first switching device is coupled to a first matched termination. A first diplexer is provided that is coupled between the first output of the directional coupler and the input of the first switching device. A first power amplifier is coupled to the first output of the first switching device, and a second diplexer is coupled between an output of the first power amplifier and the first RF output port. In these amplifiers, the first switching device is configured to pass signals received at the input to the first switching device to the first output of the first switching device when electrical power is received at the power input and is further configured to terminate signals received at the input to the first switching device through the second output of the first switching device when an electrical power feed to the power input is interrupted. 
     In some embodiments, the bi-directional RF signal amplifier may further include a second switching device and a second power amplifier that are coupled in series between the first and second diplexers. In such embodiments, the second switching device may have a first output that is coupled to an input of the second power amplifier and a second output that is coupled to a second matched termination. The first and second matched terminations may each be a resistor that is terminated to a ground voltage. The bi-directional RF signal amplifier may also include a power regulation circuit that receives electrical power from the power input and that outputs a power supply voltage. This power supply voltage may be coupled to the first power amplifier, the second power amplifier, the first switching device and the second switching device. 
     In some embodiments, the directional coupler may evenly split an input signal between its first output and its second output. In other embodiments, the directional coupler may unevenly split an input signal so as to pass more signal energy to its first output than is passed to its second output. The bi-directional RF signal amplifier may also include a power dividing circuit having an input and a plurality of outputs. This power dividing circuit may be located between the second diplexer and the first RF output port. 
     Pursuant to further embodiments of the present invention, RF signal amplifiers are provided that include an RF input port, an RF output port, and a switching device having an input that is coupled to the RF input port, a first output and a second output. The second output of the switching device is coupled to a matched termination, and a first power amplifier is coupled between the first output of the switching device and the RF output port. These signal amplifiers further include a power input for receiving electrical power, and the switching device is configured to couple the RF input port to the first output of the switching device when electrical power is received at the power input, and to couple the RF input port to the second output of the switching device when an electrical power feed to the power input is interrupted. In some embodiments, the first matched termination may be resistor that is terminated to a ground voltage. 
     In some embodiments, an input of the first power amplifier is coupled to the first output of the switching device, and an output of the first power amplifier is coupled to the RF output port. In other embodiments, an input of the first power amplifier is coupled to the RF output port, and an output of the first power amplifier is coupled to the first output of the switching device. In some embodiments, the RF signal amplifier further includes a first diplexer that is coupled between the first output of the switching device and an input to the first power amplifier and a second diplexer that is coupled between an output of the first power amplifier and the RF output port. The RF signal amplifier may also include a second power amplifier having an input that is coupled to the second diplexer and an output that is coupled to the first diplexer. 
     Pursuant to still further embodiments of the present invention, methods of automatically terminating an RF signal amplifier are provided, where the RF signal amplifier comprises a power amplifier and a switching device having a switch input that is coupled to the cable television network, a first switch output that is coupled to the power amplifier and a second switch output that is coupled to a matched termination (e.g., a resistor that is terminated to a ground voltage). Pursuant to these methods, an input of the RF signal amplifier is coupled to a cable television network. The switching device is automatically switched to connect the switch input from the first switch output to the second switch output in response to an electrical power feed to the RF signal amplifier being interrupted. In some embodiments, the switching device may be automatically switched to connect the switch input from the second switch output to the first switch output in response to the electrical power feed to the RF signal amplifier being restored. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a bi-directional RF signal amplifier employing a directional coupler for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
         FIG. 2  is a block diagram of a bi-directional RF signal amplifier employing a non-latching relay and a directional coupler for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
         FIGS. 3   a  and  3   b  are block diagrams of bi-directional RF signal amplifiers employing a plurality of non-latching relays for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
         FIGS. 4   a  and  4   b  are a circuit schematic diagram of a bi-directional RF signal amplifier employing a directional coupler for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
         FIGS. 5   a  and  5   b  are a circuit schematic diagram of a bi-directional RF signal amplifier employing a non-latching relay and a directional coupler for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
         FIGS. 6   a  and  6   b  are a circuit schematic diagram of a bi-directional RF signal amplifier employing a plurality of non-latching relays for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
         FIG. 7  is a block diagram of a bi-directional RF signal amplifier employing a terminated non-latching relay and a directional coupler for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
         FIG. 8  is a flow chart diagram illustrating methods of providing a non-interruptible communication path through a signal amplifier according to embodiments of the present invention. 
         FIG. 9   a  is a block diagram of a bi-directional RF signal amplifier employing an integrated non-latching relay and amplifier in the forward path for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
         FIG. 9   b  is a block diagram of a bi-directional RF signal amplifier employing an integrated non-latching relay and amplifier in both the forward and reverse paths for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
         FIG. 10  is a block diagram of a bi-directional RF signal amplifier employing at least one terminated integrated circuit switch and a directional coupler for facilitating a non-interruptible communication port, in accordance with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, 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 be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
     It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (i.e., “between” versus “directly between”, etc.). 
     In accordance with various embodiments set forth in the present disclosure, a bi-directional RF signal amplifier can be provided with a non-interruptible communication port for maintaining communication in the event of power failure. In various embodiments, the amplifier may receive RF signals from a service provider or any other appropriate signal source through an input port. 
     For example, in residential applications, an amplifier in accordance with various embodiments of the present disclosure may receive a composite RF signal of approximately 5 dBmV/channel in the range of approximately 5-1002 MHz comprising information for telephone, cable television (CATV), Internet, VoIP, and/or data communication from a service provider. The amplifier may increase the signal to a more useful level of approximately 20 dBmV/channel and pass the amplified signal to one or more devices in communication with the amplifier through various output ports. Such devices may include, but need not be limited to: televisions, modems, telephones, computers, and/or other communication devices known in the art. In the event of power failure, an unamplified signal may still be passed through a communication path between the service provider and the communication device. 
       FIGS. 1 ,  2 ,  3   a ,  3   b ,  7 ,  9   a ,  9   b  and  10  illustrate various embodiments of such an amplifier. Schematic representations of the embodiments of  FIGS. 1 ,  2 , and  3   a  are set forth in  FIGS. 4   a / 4   b,    5   a / 5   b,  and  6   a / 6   b,  respectively. 
       FIG. 1  illustrates a block diagram of a bi-directional RF signal amplifier  100  employing a directional coupler for facilitating a non-interruptible communication port  160 . As illustrated, amplifier  100  can support a plurality of bi-directional communication ports for sending and receiving RF signals to and from a variety of signal sources and destinations. 
     A bi-directional RF input port  110  can be provided for receiving RF signals from a service provider, or any other appropriate signal source. Input port  110  can also pass output signals in the reverse direction from the amplifier  100  through the port  110  to the service provider or other signal source. 
     A plurality of bi-directional output ports  160 ,  162 ,  164 , and  166  can also be provided by amplifier  100  for passing RF signals from the amplifier  100  to one or more devices in communication with the output ports, and vice versa. It will be appreciated that any appropriate device that may advantageously send and/or receive an RF signal may be placed in communication with one or more of the various output ports. For example, it is contemplated that telephone, CATV, Internet, VoIP, and/or data communication devices may be placed in such communication with a service provider where the amplifier  100  is installed in the residence of a subscriber. However, it will further be appreciated that any desired combination of these and/or other devices may be used where appropriate. 
     Signals received through input port  110  can be passed through a first communication path between input port  110  and output ports  162 ,  164 , and/or  166 . Specifically, the signals can be fed through a passive directional coupler  120  to a high/low diplexer  130  for separating the high frequency input signal from any low frequency output signal incident in the reverse direction. In various embodiments, diplexer  130  can filter the signals in a manner such that signals with frequencies greater than approximately 45-50 MHz are passed as high frequency input signals received from port  110 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency output signals received from ports  162 ,  164 , or  166 . 
     The high frequency input signals filtered by diplexer  130  can be amplified by individual amplifier  140 , and passed to high/low diplexer  135  where they are combined with the output signals. The recombined signal can then be provided to power dividers  150 , where it is distributed to any of ports  162 ,  164 , and/or  166 . 
     Turning now to the reverse signal flow through the first communication path of amplifier  100 , signals received by the amplifier  100  from devices in communication with ports  162 ,  164 , and/or  166  can be passed to power dividers  150  where they are combined into a composite output signal. The output signal can be fed through high/low diplexer  135  for separating the low frequency output signal from any high frequency input signal incident in the forward direction. As previously discussed in relation to diplexer  130 , the diplexer  135  can filter the signals such that signals with frequencies greater than approximately 45-50 MHz are passed in the forward direction as high frequency signals received from port  110 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency signals received from ports  162 ,  164 , and/or  166 . 
     The low frequency output signals filtered by diplexer  135  can be amplified by individual amplifier  145 , and passed to high/low diplexer  130  where they are combined with the input signals. In various embodiments, individual amplifier  145  can optionally be omitted from amplifier  100 . The recombined signal can then be provided to coupler  120  where it is passed to port  110  for output to a service provider or other entity in communication with port  110 . 
     As illustrated, amplifier  100  can further provide a power passing path  188 , allowing power to be transmitted between ports  110  and  160 . 
     During normal operation, the amplifier  100  can be powered from a power input port  170  and/or power that is reverse fed through RF OUT N/VDC IN port  166 . In a typical installation at a subscriber&#39;s residence, it is contemplated that amplifier  100  may be powered by an AC/DC adapter receiving power provided by the residence (for example, 100-230 VAC, 50/60 Hz). As illustrated in  FIG. 1 , the power received from either power input can be provided to a voltage regulator  175  which supplies an operating voltage VCC to individual amplifiers  140  and/or  145 . 
     In the event that power to voltage regulator  175  is interrupted, voltage regulator  175  will be unable to provide operating voltage VCC to individual amplifiers  140  and/or  145 . As a result, individual amplifier  140  will not function to amplify the input signals received through port  110  for proper distribution to the various output ports  162 ,  164 , and/or  166 . Similarly, individual amplifier  145  also will not function to amplify the output signals received from ports  162 ,  164 , and/or  166 . 
     In response to this situation, amplifier  100  further provides a second communication path—a path between input port  110  and output port  160 . In this regard, a dedicated non-interruptible port  160  can communicate with port  110  through coupler  120 . Using this second communication path between ports  110  and  160  through coupler  120 , signals can still be passed between a device in communication with port  160  and a service provider in communication with port  110 . It will be appreciated that although the second communication path of amplifier  100  does not necessarily amplify the input or output signals, the path can nevertheless permit communication of at least one or more services, such as emergency 911 telephone service. 
     It will be appreciated that the use of the second communication path between ports  110  and  160  can provide a significant advantage in ensuring the availability of communication to at least one communication device in the event of power failure. A communication device in communication with port  160  (such as a VoIP compatible device, or other device) can further be provided with backup battery power to maintain the operation of the communication device. As discussed above, a schematic representation of the amplifier  100  of  FIG. 1  is set forth in  FIGS. 4   a  and  4   b.    
       FIG. 2  illustrates a block diagram of a bi-directional RF signal amplifier  200  employing a non-latching relay  221  and a directional coupler  225  for maintaining a non-interruptible communication port  260 . As illustrated, amplifier  200  can support a plurality of bi-directional communication ports for sending and receiving RF signals to and from a variety of signal sources and destinations. 
     Similar to amplifier  100  previously discussed herein, amplifier  200  includes a bi-directional RF input port  210  for receiving RF signals from a service provider, or any other appropriate signal source. Input port  210  can also pass output signals in the reverse direction from the amplifier  200  through the port  210  to the service provider or other signal source. 
     A plurality of bi-directional output ports  260 ,  262 , and  266  can also be provided by amplifier  200  for passing RF signals from the amplifier  200  to one or more devices in communication with the output ports, and vice versa. Similar to amplifier  100 , it will be appreciated that any appropriate device that may advantageously send and/or receive an RF signal may be placed in communication with one or more of the various output ports of amplifier  200 . For example, it is contemplated that telephone, CATV, Internet, VoIP, and/or data communication devices may be placed in such communication where the amplifier  200  is installed in the residence of a subscriber. However, it will further be appreciated that any desired combination of these and/or other devices may be used where appropriate. 
     Signals received through input port  210  can be passed through a first communication path between input port  210  and output ports  260 ,  262 , and/or  266 . Specifically, the signals can be fed through a SPDT non-latching relay  221  to a high/low diplexer  230  for separating the high frequency input signal from any low frequency output signal incident in the reverse direction. In various embodiments, diplexer  230  can filter the signals in a manner such that signals with frequencies greater than approximately 45-50 MHz are passed as high frequency input signals received from input port  210 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency output signals received from ports  260 ,  262 , or  266 . 
     The high frequency input signals filtered by diplexer  230  can be amplified by individual amplifier  240 , and passed to high/low diplexer  235  where they are combined with the output signals. The recombined signal can then be provided to power dividers  250 , where it is distributed to any of ports  260 ,  262 , and/or  266 . 
     Turning now to the reverse signal flow through the first communication path of amplifier  200 , signals received by the amplifier  200  from devices in communication with ports  262  and/or  266  can be passed to power dividers  250  where they are combined into a composite output signal. Signals received through port  260  can be passed to power dividers  250  through passive directional coupler  225  and also combined into the composite signal. The output signal can be fed through high/low diplexer  235  for separating the low frequency output signal from any high frequency input signal incident in the forward direction. As previously discussed in relation to diplexer  230 , the diplexer  235  can filter the signals such that signals with frequencies greater than approximately 45-50 MHz are passed in the forward direction as high frequency signals received from port  210 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency signals received from ports  260 ,  262 , and/or  266 . 
     The low frequency output signals filtered by diplexer  235  can be amplified by individual amplifier  245 , and passed to high/low diplexer  230  where they are combined with the input signals. In various embodiments, individual amplifier  245  can optionally be omitted from amplifier  200 . The recombined signal can then be provided to non-latching relay  221  where it is passed to port  210  for output to a service provider or other entity in communication with port  210 . 
     As illustrated, amplifier  200  can further provide a power passing path  280 , allowing power to be transmitted between ports  210  and  260 . 
     During normal operation, the amplifier  200  can be powered from a power input port  270  and/or power that is reverse fed through RF OUT N/VDC IN port  266 . In a typical installation at a subscriber&#39;s residence, it is contemplated that amplifier  200  may be powered by an AC/DC adapter receiving power provided by the residence (for example, 100-230 VAC, 50/60 Hz). As illustrated in  FIG. 2 , the power received from either power input can be provided to a voltage regulator  275  which supplies an operating voltage VCC to individual amplifiers  240  and/or  245 . 
     In the event that power to voltage regulator  275  is interrupted, voltage regulator  275  will be unable to provide operating voltage VCC to individual amplifiers  240  and/or  245 . As a result, individual amplifier  240  will not function to amplify the input signals received through port  210  for proper distribution to the various output ports  260 ,  262 , and/or  266 . Similarly, individual amplifier  245  also will not function to amplify the output signals received from ports  260 ,  262 , and/or  266 . 
     Accordingly, amplifier  200  further provides a second communication path between input port  210  and output port  260 . In this regard, a dedicated non-interruptible port  260  can communicate with port  210  through relay  221  and coupler  225 . As illustrated, amplifier  200  provides a VCC path  223  to relay  221 . When power (i.e. VCC) is interrupted, the relay  221  will be caused to switch from the normal signal path in the “set” position, to the non-interruptible signal path in the “reset” position or vice versa. As a result, using the non-interruptible signal path between ports  210  and  260  through relay  221  and coupler  225 , signals can still be passed between a device in communication with port  260  and a service provider in communication with port  210 . It will be appreciated that although the second communication path of amplifier  200  does not necessarily amplify the input or output signals, the path can nevertheless permit communication of at least one or more services, such as emergency 911 telephone service. 
     It will be appreciated that the use of the second communication path between ports  210  and  260  can provide a significant advantage in ensuring the availability of communication to at least one communication device in the event of power failure. A communication device in communication with port  260  (such as a VoIP compatible device, or other device) can further be provided with backup battery power to maintain the operation of the communication device. As discussed above, a schematic representation of the amplifier  200  of  FIG. 2  is set forth in  FIGS. 5   a  and  5   b.    
       FIG. 3   a  illustrates a block diagram of a bi-directional RF signal amplifier  300  employing a plurality of non-latching relays for facilitating a non-interruptible communication port  360 . As illustrated, amplifier  300  can support a plurality of bi-directional communication ports for sending and receiving RF signals to and from a variety of signal sources and destinations. 
     Similar to amplifiers  100  and  200  previously discussed herein, amplifier  300  includes a bi-directional RF input port  310  for receiving RF signals from a service provider, or any other appropriate signal source. Input port  310  can also pass output signals in the reverse direction from the amplifier  300  through the port  310  to the service provider or other signal source. 
     A plurality of bi-directional output ports  360 ,  362 , and  366  can also be provided by amplifier  300  for passing RF signals from the amplifier  300  to one or more devices in communication with the output ports, and vice versa. Similar to amplifiers  100  and  200 , it will be appreciated that any appropriate device that may advantageously send and/or receive an RF signal may be placed in communication with one or more of the various output ports of amplifier  300 . For example, it is contemplated that telephone, CATV, Internet, VoIP, and/or data communication devices may be placed in such communication where the amplifier  300  is installed in the residence of a subscriber to a service provider. However, it will further be appreciated that any desired combination of these and/or other devices may be used where appropriate. 
     Signals received through input port  310  can be passed through a first communication path between input port  310  to output ports  360 ,  362 , and/or  366 . Specifically, the signals can be fed through a non-latching relay  320  to a high/low diplexer  330  for separating the high frequency input signal from any low frequency output signal incident in the reverse direction. In various embodiments, diplexer  330  can filter the signals in a manner such that signals with frequencies greater than approximately 45-50 MHz are passed as high frequency input signals received from port  310 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency output signals received from ports  360 ,  362 , or  366 . 
     The high frequency input signals filtered by diplexer  330  can be amplified by individual amplifier  340 , and passed to high/low diplexer  335  where they are combined with the output signals. The recombined signal can then be provided to power dividers  350 , where it is distributed to any of ports  360 ,  362 , and/or  366 . As illustrated, signals provided to port  360  through a SPDT non-latching relay  325  can further be passed through an attenuator pad  390  for reducing the strength of the amplified signal (approximately 20 dBmV/channel) by approximately 5 dBmV/channel. 
     Turning now to the reverse signal flow through the first communication path of amplifier  300 , signals received by the amplifier  300  from devices in communication with ports  362  and/or  366  can be passed to power dividers  350  where they are combined into a composite output signal. Signals received through port  360  can be passed to power dividers  350  through non-latching relay  325  and attenuator pad  390 , and also combined into the composite signal. The output signal can be fed through high/low diplexer  335  for separating the low frequency output signal from any high frequency input signal incident in the forward direction. As previously discussed in relation to diplexer  330 , the diplexer  335  can filter the signals such that signals with frequencies greater than approximately 45-50 MHz are passed in the forward direction as high frequency signals received from port  310 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency signals received from ports  360 ,  362 , and/or  366 . 
     The low frequency output signals filtered by diplexer  335  can be amplified by individual amplifier  345 , and passed to high/low diplexer  330  where they are combined with the input signals. In various embodiments, individual amplifier  345  can optionally be omitted from amplifier  300 . The recombined signal can then be provided to SPDT non-latching relay  320  where it is passed to port  310  for output to a service provider or other entity in communication with port  310 . 
     As illustrated, amplifier  300  can further provide a power passing path  380 , allowing power to be transmitted between ports  310  and  360 . 
     During normal operation, the amplifier  300  can be powered from a power input port  370  and/or power that is reverse fed through RF OUT N/VDC IN port  366 . In a typical installation at a subscriber&#39;s residence, it is contemplated that amplifier  300  may be powered by an AC/DC adapter receiving power provided by the residence (for example, 100-230 VAC, 50/60 Hz). As illustrated in  FIG. 3 , the power received from either power input can be provided to a voltage regulator  375  which supplies an operating voltage VCC to individual amplifiers  340  and/or  345 . 
     In the event that power to voltage regulator  375  is interrupted, voltage regulator  375  will be unable to provide operating voltage VCC to individual amplifiers  340  and/or  345 . As a result, individual amplifier  340  will not function to amplify the input signals received through port  310  for proper distribution to the various output ports  360 ,  362 , and/or  366 . Similarly, individual amplifier  345  also will not function to amplify the output signals received from ports  360 ,  362 , and/or  366 . 
     As a result, amplifier  300  further provides a second communication path between input port  310  and output port  360 . In this regard, a dedicated non-interruptible port  360  can communicate with port  310  through relay  320  and relay  325 . As illustrated, amplifier  300  provides a VCC path  323  to relay  320 , and a second VCC path  327  to relay  325 . When power (i.e. VCC) is interrupted, the relays  320  and  325  will be caused to switch from the normal signal path in the “set” positions, to the non-interruptible signal path in the “reset” positions or vice versa. As a result, using the non-interruptible signal path between ports  310  and  360  through relays  320  and  325 , signals can still be passed between a device in communication with port  360  and a service provider in communication with port  310 . It will be appreciated that although the second communication path of amplifier  300  does not necessarily amplify the input or output signals, the path can nevertheless permit communication of at least one or more services, such as emergency 911 telephone service. 
     It will be appreciated that the use of the second communication path between ports  310  and  360  can provide a significant advantage in ensuring the availability of communication to at least one communication device in the event of power failure. A communication device in communication with port  360  (such as a VoIP compatible device, or other device) can further be provided with backup battery power to maintain the operation of the communication device. As discussed above, a schematic representation of the amplifier  300  of  FIG. 3   a  is set forth in  FIGS. 6   a  and  6   b.    
       FIG. 3   b  illustrates a block diagram of an alternate embodiment of bi-directional RF signal amplifier  300 . As illustrated, the embodiment of  FIG. 3   b  revises the connections of relay  325 , diplexers  335 , and power dividers  350 . It will be appreciated that the embodiment of  FIG. 3   b  allows each of the output ports  360 ,  362 , and  366  to be switched. It will further be appreciated that a schematic representation of the embodiment of  FIG. 3   b  can be provided through appropriate manipulation of the schematic of  FIGS. 6   a  and  6   b.   
       FIG. 7  is a block diagram of a bi-directional RF signal amplifier  400  employing a non-latching relay  421  and a directional coupler  425  for maintaining a non-interruptible communication port  466 . As illustrated, amplifier  400  can support a plurality of bi-directional communication ports for sending and receiving RF signals to and from a variety of signal sources and destinations. 
     Similar to amplifier  100  previously discussed herein, amplifier  400  includes a bi-directional RF input port  410  for receiving RF signals from a service provider, or any other appropriate signal source. RF input port  410  can also pass output signals in the reverse direction from the amplifier  400  through the port  410  to the service provider or other signal source. 
     A plurality of bi-directional output ports  460 ,  462 ,  464  and  466  can also be provided by amplifier  400  for passing RF signals from the amplifier  400  to one or more devices in communication with the output ports, and vice versa. Similar to amplifier  100 , it will be appreciated that any appropriate device that may advantageously send and/or receive an RF signal may be placed in communication with one or more of the various output ports  460 ,  462 ,  464  and/or  466  of amplifier  400 . For example, it is contemplated that telephone, CATV, Internet, VoIP, and/or data communication devices may be placed in such communication where the amplifier  400  is installed in the residence of a subscriber to a service provider. However, it will further be appreciated that any desired combination of these and/or other devices may be used where appropriate. 
     Signals received through input port  410  can be passed through a passive directional coupler  425  to first and second communications paths. It will be appreciated that the directional coupler  425  may either evenly or unevenly split the power of the input signals between the first and second communications path, depending on the design of the overall circuit. As shown in  FIG. 7 , the first communication path includes an SPDT non-latching relay  421 , a high/low diplexer  430 , a power amplifier  440 , a power amplifier  445 , a high/low diplexer  435  and 1×N power dividers  450 , which components connect the first output of the directional coupler  425  to the output ports  460 ,  462  and  464 . In particular, the signals output by directional coupler  425  to the first communications path are first input to an SPDT non-latching relay  421 . When the non-latching relay  421  is in the “ON” or “SET” state, these signals then pass to a high/low diplexer  430  for separating the high frequency input signal from any low frequency output signal incident in the reverse direction. In various embodiments, diplexer  430  can filter the signals in a manner such that signals with frequencies greater than approximately 45-50 MHz are passed as high frequency input signals received from port  410 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency output signals received from ports  460 ,  462 , and/or  464 . 
     The high frequency input signals filtered by diplexer  430  can be amplified by individual amplifier  440 , and passed to high/low diplexer  435 . The output of diplexer  435  is then provided to 1×N power dividers  450 , where it is distributed to any of ports  460 ,  462 , and/or  464 . 
     Turning now to the reverse signal flow through the first communication path of amplifier  400 , signals received by the amplifier  400  from devices in communication with ports  460 ,  462  and/or  464  can be passed to power dividers  450  where they are combined into a composite output signal. This composite output signal can be fed through high/low diplexer  435  for separating the low frequency output signal from any high frequency input signal incident in the forward direction. As previously discussed in relation to diplexer  430 , the diplexer  435  can filter the signals such that signals with frequencies greater than approximately 45-50 MHz are passed in the forward direction as high frequency signals received from port  410 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency signals received from ports  460 ,  462 , and/or  464 . 
     The low frequency output signals filtered by diplexer  435  can be amplified by individual amplifier  445 , and passed to high/low diplexer  430  where they are combined with the input signals. In various embodiments, individual amplifier  445  can optionally be omitted from amplifier  400 . The recombined signal can then be provided to non-latching relay  421  where it is passed to the RF input port  410  via the directional coupler  425  for output to a service provider or other entity in communication with the RF input port  410 . The amplifiers  440  and  445  may have different gains. For example, in some embodiments, amplifier  440  may have about 18 dB gain, while amplifier  445  may have about 15 dB gain. An attenuator (not shown in  FIG. 7 ) may also be provided, for example, between amplifier  445  and diplexer  435 . 
     During normal operation, the amplifier  400  can be powered from a power input port  470  and/or power that is reverse fed through RF OUT N/VDC IN port  464 . In a typical installation at a subscriber&#39;s residence, it is contemplated that amplifier  400  may be powered by an AC/DC adapter receiving power provided by the residence (for example, 100-230 VAC, 50/60 Hz). As illustrated in  FIG. 7 , the power received from either power input can be provided to a voltage regulator  475  which supplies an operating voltage VCC to individual amplifiers  440  and/or  445 . 
     In the event that power to voltage regulator  475  is interrupted, voltage regulator  475  will be unable to provide operating voltage VCC to individual amplifiers  440  and/or  445 . As a result, individual amplifier  440  will not function to amplify the input signals received through port  410  for proper distribution to the various output ports  460 ,  462 , and/or  464 . Similarly, individual amplifier  445  also will not function to amplify the output signals received from ports  460 ,  462 , and/or  464 . 
     Accordingly, amplifier  400  further provides a second, non-interruptible communication path between input port  410  and Voice Over IP (VOIP) output port  466 . In particular, as shown in  FIG. 7 , the signals output by directional coupler  425  to the second communications path may be passed directly to the VOIP output port  466 . 
     Thus, in the embodiment of  FIG. 7 , the directional coupler  425  is used to split a signal received through input port  410  into two separate components, and delivers the first component of the split signal to RF output ports  460 ,  462  and  464  via a first communication path and delivers the second component of the split signal to VOIP port  466  via a second communication path. Consequently, even if power is interrupted such that the amplifiers  440  and  445  are rendered inoperable, a second, non-interruptible communication path still exists between RF input port  410  and VOIP port  466  which can be used to support communication of at least one or more services, such as emergency 911 telephone service. 
     As is also illustrated in  FIG. 7 , amplifier  400  provides a VCC path  422  to relay  421 . When power (i.e., VCC) is interrupted, the relay  421  will be caused to switch from the normal signal path in the “ON” (or “SET”) position, to the “OFF” (or “RESET”) position (or vice versa when power is resumed). The second output port of relay  421  (the “OFF” port) is connected to a matched resistive termination (here a 75 ohm resistor  442 ). When the power supply is interrupted, the relay  421  senses the interruption and switches from the “ON” position to the “OFF” position. As the OFF position of relay  421  is coupled to the matched resistive termination, both outputs of the directional coupler  425  are matched. As such, signal degradation due to reflections and the like can be reduced or minimized in order to provide acceptable signal quality on the second, non-interruptible communications path. 
     It will be appreciated that providing a second, non-interruptible communication path between ports  410  and  466  can provide a significant advantage in ensuring the availability of communication to at least one communication device in the event of power failure. A communication device in communication with port  466  (such as a VoIP compatible device, or other device) can further be provided with backup battery power to maintain the operation of the communication device. 
     As should be clear from the above description, the amplifier  400  of  FIG. 7  includes a selective termination circuit that is configured to pass signals between the RF input port and the first RF output port over the first communication path when electrical power is received at the power input and that is further configured to terminate the first communication path to a matched termination when an electrical power feed to the power input is interrupted. In the particular embodiment of  FIG. 7 , this selective termination circuit comprises a relay that completes the first communication path when electrical power is received at the power input, but terminates the first communication path to a matched termination when an electrical power feed to the power input is interrupted. 
     Herein, the term “matched termination” is used to refer to a termination that approximately matches the specific transmission paths impedance (in this case 75 ohms), thus being capable of substantially absorbing the possible propagation modes with minimal reflection. The term “resistive termination” is used to refer to a termination that includes at least one purposefully resistive element such as a resistor. By providing such a matched resistive termination in signal amplifier  400 , the directional coupler may be configured to have two impedance matched output terminals even when the integrated circuit chip containing the power amplifiers  440  and  445  shuts down for lack of power, and hence reflections that result in return loss, frequency response and/or other signal degradation can be reduced in these circumstances. This may significantly improve the signal quality on the second, non-interruptible communication path (in both the forward and reverse directions) when the first communication path is inactive (i.e., terminated to the matched resistive termination). 
       FIG. 8  is a flow chart illustrating methods of providing a non-interruptible communication path through a signal amplifier that includes an RF input port and multiple RF output ports according to embodiments of the present invention. As shown in  FIG. 8 , pursuant to these methods, a directional coupler may be used to split a signal received at the RF input port into a first signal component and a second signal component (block  500 ). The signal may comprise, for example, a composite signal from a service provider that includes CATV signals, broadband Internet traffic and/or Internet telephone service traffic. The directional coupler may comprise a splitter that evenly divides the signal energy of the input signal when it splits the signal into the first and second components, or may comprise a weighted directional coupler that provides more of the signal energy to one of the components (e.g., the first component) than to the second component. As is further shown in  FIG. 8 , the first component is coupled to one or more output ports of the signal amplifier via a first communication path, such as, for example, the first communication path illustrated in  FIG. 7  (block  510 ). Likewise, the second component is coupled to a different output port of the signal amplifier via a second communication path, such as, for example, the second communication path illustrated in  FIG. 7  (block  520 ). At some point, the power feed to the signal amplifier is interrupted. In response to this interruption, the first component of the input signal is routed to a matched resistive termination (block  530 ). 
       FIG. 9   a  is a block diagram of a bi-directional RF signal amplifier  500  employing an integrated circuit chip  532  in the forward path that includes a non-latching relay  521  and an amplifier  540  for facilitating a non-interruptible communication port  564 . As illustrated, amplifier  500  can support a plurality of bi-directional communication ports for sending and receiving RF signals to and from a variety of signal sources and destinations. 
     Amplifier  500  includes a bi-directional RF input port  510  for receiving RF signals from a service provider, or any other appropriate signal source. RF input port  510  can also pass output signals in the reverse direction from the amplifier  500  through the port  510  to the service provider or other signal source. 
     A plurality of bi-directional output ports  560 ,  562  and  564  can also be provided by amplifier  500  for passing RF signals from the amplifier  500  to one or more devices in communication with the output ports, and vice versa. It will be appreciated that any appropriate device that may advantageously send and/or receive an RF signal may be placed in communication with one or more of the various output ports  560 ,  562  and/or  564  of amplifier  500 . For example, it is contemplated that telephone, CATV, Internet, VoIP, and/or data communication devices may be placed in such communication where the amplifier  500  is installed in the residence of a subscriber to a service provider. However, it will further be appreciated that any desired combination of these and/or other devices may be used where appropriate. 
     Signals received through input port  510  can be passed directly to a high/low diplexer  530  that separates the high frequency input signal from any low frequency output signal incident in the reverse direction. In various embodiments, diplexer  530  can filter the signals in a manner such that signals with frequencies greater than approximately 45-50 MHz are passed as high frequency input signals received from port  510 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency output signals received from ports  560 ,  562 , and/or  564 . The high frequency input signals filtered by diplexer  530  are passed to an SPDT non-latching relay  521 . When the non-latching relay  521  is in the “ON” or “SET” state, these signals then pass to a power amplifier  540 , then to a high/low diplexer  535  and 1×N power dividers  550  where the signals are passed to the output ports  560 ,  562  and  564 . 
     Turning now to the reverse signal flow through amplifier  500 , signals received by the amplifier  500  from devices in communication with ports  560 ,  562  and/or  564  can be passed to power dividers  550  where they are combined into a composite output signal. This composite output signal can be fed through high/low diplexer  535  for separating the low frequency output signal from any high frequency input signal incident in the forward direction. As previously discussed in relation to diplexer  530 , the diplexer  535  can filter the signals such that signals with frequencies greater than approximately 45-50 MHz are passed in the forward direction as high frequency signals received from port  410 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency signals received from ports  560 ,  562 , and/or  564 . 
     The low frequency output signals filtered by diplexer  535  are passed without amplification to high/low diplexer  530  where they are combined with the input signals. The recombined signal can then be passed to the RF input port  510  for output to a service provider or other entity in communication with the RF input port  510 . 
     During normal operation, the amplifier  500  can be powered from a power input port  570  and/or power that is reverse fed through RF OUT N/VDC IN port  564 . In a typical installation at a subscriber&#39;s residence, it is contemplated that amplifier  500  may be powered by an AC/DC adapter receiving power provided by the residence (for example, 100-230 VAC, 50/60 Hz). As illustrated in  FIG. 9   a , the power received from either power input can be provided to a voltage regulator  575  which supplies an operating voltage VCC to individual amplifier  540 . 
     In the event that power to voltage regulator  575  is interrupted, voltage regulator  575  will be unable to provide operating voltage VCC to individual amplifier  540 . As a result, individual amplifier  540  will not function to amplify the input signals received through port  510  for proper distribution to the various output ports  560 ,  562 , and/or  564 . 
     Accordingly, amplifier  500  further provides a second, non-interruptible communication path between input port  510  and the output ports  560 ,  562  and, in particular, Voice Over IP (VOIP) output port  564 . More particularly, when power (i.e., VCC) is interrupted, the relay  521  will be caused to switch from the normal signal path in the “ON” (or “SET”) position, to the “OFF” (or “RESET”) position (or vice versa when power is resumed). The second output port of relay  521  (the “OFF” port) is connected so as to bypass the amplifier  540 , thus providing a second, non-interruptible communications path between diplexer  530  and diplexer  535 . When the power supply is interrupted, the relay  521  senses the interruption and switches from the “ON” position to the “OFF” position, thereby activating the non-interruptible (and non-amplified) communications path. Consequently, even if power is interrupted such that the amplifier  540  is rendered inoperable, a second, non-interruptible communication path still exists between RF input port  510  and VOIP port  564  which can be used to support communication of at least one or more services, such as emergency 911 telephone service. Note that in the embodiment of  FIG. 9   a , any of the output ports may be the VOIP port (i.e., it does not have to be output port  564 ). 
     It will be appreciated that providing a second, non-interruptible communication path between ports  510  and  564  can provide a significant advantage in ensuring the availability of communication to at least one communication device in the event of power failure. A communication device in communication with port  564  (such as a VoIP compatible device, or other device) can further be provided with backup battery power to maintain the operation of the communication device. 
     In some embodiments, the non-latching relay  521  and the amplifier  540  may be implemented on a single integrated circuit chip  532 . It will also be appreciated that in some embodiments, the integrated circuit chip  532  may include one or more additional relays. By way of example, the integrated circuit chip  532  may include a second relay that together with relay  521  physically disconnect the amplifier  540  from the electrical path. this configuration may further improve the impedance match of the bypass trace (i.e., the trace from the second output of relay  521  to the diplexer  535 ). 
       FIG. 9   b  is a block diagram of a bi-directional RF signal amplifier  600  that includes a first integrated circuit chip  532  in the forward path that includes a non-latching relay  521  and an amplifier  540 , and a second integrated circuit chip  633  in the reverse path that includes a non-latching relay  623  and an amplifier  645  for facilitating a non-interruptible communication port  564 . The RF signal amplifier  600  may be nearly identical to the RF signal amplifier  500  of  FIG. 9   a , except that the RF signal amplifier  600  employs a second integrated circuit chip  633  in the reverse path that includes a non-latching relay  623  and an amplifier  645 . Consequently, circuit elements of RF signal amplifier  600  that are identical to the corresponding circuit elements of RF signal amplifier  500  of  FIG. 9   a  are given like reference numerals, and these circuit elements and the operation thereof will not be described further herein. 
     As noted above, the difference between RF signal amplifier  600  of  FIG. 9   b  and the RF signal amplifier  500  of  FIG. 9   a  is the inclusion of a second integrated circuit chip  633  in the reverse path. This second integrated circuit chip  633  has a non-latching relay  623  and an amplifier  645 . During normal operation, the amplifier  645  is powered by VCC and the non-latching relay  623  is in the “ON” or “SET” state so that signals in the reverse path are passed through power amplifier  645 . However, if power to voltage regulator  575  is interrupted, the relay  623  senses the interruption and switches from the “ON” position to the “OFF” position. The second output port of relay  623  (the “OFF” port) is connected so as to bypass the amplifier  645 , thus providing a second, non-interruptible communications path in the reverse direction between diplexer  535  and diplexer  530 . Thus, the RF signal amplifier  600  provides amplification in the reverse direction during normal operation, while still providing non-interruptible (and non-amplified) communications paths in both the forward and reverse directions when power is interrupted. 
       FIG. 10  is a block diagram of a bi-directional RF signal amplifier  700  according to further embodiments of the present invention. The bi-directional RF signal amplifier  700  includes a directional coupler  725  and two integrated circuit RF relay chips  721 ,  723 . As illustrated, amplifier  700  can support a plurality of bi-directional communication ports for sending and receiving RF signals to and from a variety of signal sources and destinations. 
     Similar to amplifier  100  previously discussed herein, amplifier  700  includes a bi-directional RF input port  710  for receiving RF signals from a service provider, or any other appropriate signal source. RF input port  710  can also pass output signals in the reverse direction from the amplifier  700  to the service provider or other signal source. 
     A plurality of bi-directional output ports  760 ,  762 ,  764  and  766  are also provided for passing RF signals from the amplifier  700  to one or more devices in communication with the output ports, and vice versa. Similar to amplifier  100 , it will be appreciated that any appropriate device that may advantageously send and/or receive an RF signal may be placed in communication with one or more of the various output ports  760 ,  762 ,  764  and/or  766  of amplifier  700 . For example, it is contemplated that telephone, CATV, Internet, VoIP, and/or data communication devices may be placed in such communication where the amplifier  700  is installed in the residence of a subscriber to a service provider. However, it will further be appreciated that any desired combination of these and/or other devices may be used where appropriate. 
     Signals received through input port  710  can be passed through a passive directional coupler  725  to first and second communications paths. It will be appreciated that the directional coupler  725  may either evenly or unevenly split the power of the input signals between the first and second communications paths, depending on the design of the overall circuit. As shown in  FIG. 10 , the first communication path includes high/low diplexer  730 , an integrated circuit RF relay chip  721 , a power amplifier  740 , an integrated circuit RF relay chip  723 , a power amplifier  745 , a high/low diplexer  735  and 1×N power dividers  750 , which components connect the first output of the directional coupler  725  to the output ports  760 ,  762  and  764  (which are three of the exemplary seven output ports attached to the 1×N power divider  750  of the embodiment of  FIG. 10 ). In particular, the signals output by directional coupler  725  in the forward direction to the first communications path are first input to the high/low diplexer  730  for separating the high frequency input signal from any low frequency output signal incident in the reverse direction. In various embodiments, diplexer  730  can filter the signals in a manner such that signals with frequencies greater than approximately 45-50 MHz are passed as high frequency input signals received from port  710 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency output signals received from ports  760 ,  762 , and/or  764 . 
     The high frequency input signals filtered by diplexer  730  are passed to integrated circuit chip RF relay  721 . When the relay  721  is in the “ON” or “SET” state, these signals then pass to an individual amplifier  740  for amplification, and then are passed from the output of the amplifier  740  to high/low diplexer  735 . The output of diplexer  735  is then provided to 1×N power dividers  750 , where it is distributed to any of ports  760 ,  762 , and/or  764 . In the particular embodiment depicted in  FIG. 10 , the 1×N power dividers  750  may be a 1×8 power divider. Seven of the outputs of 1×N power divider  750  are connected to respective of first through seventh RF output ports, while the eighth output is terminated to ground via a 75 ohm resistor. 
     Turning now to the reverse signal flow through the first communication path of amplifier  700 , signals received by the amplifier  700  from devices in communication with ports  760 ,  762  and/or  764  can be passed to power dividers  750  where they are combined into a composite output signal. This composite output signal can be fed through high/low diplexer  735  for separating the low frequency output signal from any high frequency input signal incident in the forward direction. As previously discussed in relation to diplexer  730 , the diplexer  735  can filter the signals such that signals with frequencies greater than approximately 45-50 MHz are passed in the forward direction as high frequency signals received from port  710 , while signals with frequencies lower than such range are passed in the reverse direction as low frequency signals received from ports  760 ,  762 , and/or  764 . 
     The low frequency output signals filtered by diplexer  735  can be amplified by individual amplifier  745 , and passed to integrated circuit chip RF relay  723 . When the relay  723  is in the “ON” or “SET” state, these signals then pass to high/low diplexer  730  where they are combined with the input signals. The recombined signal can then be passed to the RF input port  710  via the directional coupler  725  for output to a service provider or other entity in communication with the RF input port  710 . The amplifiers  740  and  745  may have different gains. For example, in some embodiments, amplifier  740  may have about 18 dB gain, while amplifier  745  may have about 15 dB gain. An attenuator (not shown in  FIG. 10 ) may also be provided, for example, between amplifier  745  and diplexer  735 . It will also be appreciated that in some embodiments, individual amplifier  745  and/or relay  723  can optionally be omitted from amplifier  700 . 
     During normal operation, the amplifier  700  can be powered from a power input port  770  and/or power that is reverse fed through, for example, RF OUT  7 /VDC IN port  764 . In a typical installation at a subscriber&#39;s residence, it is contemplated that amplifier  700  may be powered by an AC/DC adapter receiving power provided by the residence (for example, 100-230 VAC, 50/60 Hz). As illustrated in  FIG. 10 , the power received from either power input can be provided to a voltage regulator  775  which supplies an operating voltage VCC to individual amplifiers  740  and/or  745 . 
     In the event that power to voltage regulator  775  is interrupted, voltage regulator  775  will be unable to provide operating voltage VCC to individual amplifiers  740  and/or  745 . As a result, individual amplifier  740  will not function to amplify the input signals received through port  710  for proper distribution to the various output ports  760 ,  762 , and/or  764 . Similarly, individual amplifier  745  also will not function to amplify the output signals received from ports  760 ,  762 , and/or  764 . 
     Accordingly, amplifier  700  further provides a second, non-interruptible communication path between input port  710  and Voice Over IP (VOIP) output port  766 . In particular, as shown in  FIG. 10 , the signals output by directional coupler  725  to the second communications path may be passed directly to the VOIP output port  766 . 
     Thus, in the embodiment of  FIG. 10 , the directional coupler  725  is used to split a signal received through input port  710  into two separate components, and delivers the first component of the split signal to RF output ports  760 ,  762  and  764  via a first communication path and delivers the second component of the split signal to VOIP port  766  via a second communication path. Consequently, even if power is interrupted such that the amplifiers  740  and  745  are rendered inoperable, a second, non-interruptible communication path still exists between RF input port  710  and VOIP port  766  which can be used to support communication of at least one or more services, such as emergency 911 telephone service. 
     As is also illustrated in  FIG. 10 , amplifier  700  provides a VCC path  722  to relays  721  and  723 . When power (i.e., VCC) is interrupted, the relays  721 ,  723  will each switch from the normal signal path in the “ON” (or “SET”) position, to the “OFF” (or “RESET”) position (or vice versa when power is resumed). The respective second output ports of relay  721  and  723  (the “OFF” ports) are each connected to a matched resistive termination (here a 75 ohm resistor). When the power supply is interrupted, the relays  721  and  723  sense the power supply interruption and they each switch from the “ON” position to the “OFF” position. As the OFF positions of relays  721  and  723  are each coupled to a matched resistive termination, both outputs of the directional coupler  725  are matched. As such, signal degradation due to reflections and the like can be reduced or minimized in order to provide acceptable signal quality on the second, non-interruptible communications path. 
     In some embodiments, the relay  721  and the amplifier  740  may be implemented on a single integrated circuit chip, and/or the relay  723  and the amplifier  745  may be implemented on a single integrated circuit chip. It will also be appreciated that in some embodiments, the relays  721  and  723  and the power amplifiers  740 ,  745  may all be implemented on a single integrated circuit chip. 
     It will be appreciated that providing a second, non-interruptible communication path between ports  710  and  766  can provide a significant advantage in ensuring the availability of communication to at least one communication device in the event of power failure. A communication device in communication with port  766  (such as a VoIP compatible device, or other device) can further be provided with backup battery power to maintain the operation of the communication device. 
     The bi-directional RF signal amplifier  700  of  FIG. 10  may provide improved performance in applications where significant signal power is carried along the reverse path. In particular, in embodiments such as the embodiment of  FIG. 7  where the relay  421  is located in a common path that carries signals in both the forward and reverse directions, distortion by-product signals may be generated in the relay  421 . To the extent that these distortion by-product signals are within the frequency range passed by the high side of the first diplexer  430 , the distortion by-product signals will pass to the first amplifier  440  where they are amplified and passed to the RF output ports  460 ,  462 ,  464 . However, in the embodiment of  FIG. 10 , the first and second relays  721 ,  723  are located between the first and second diplexers  730 ,  735 . Consequently, any distortion by-product signals generated in the relay  723  that fall within the frequency range passed by the high side of the first diplexer  730  will be isolated by the diplexer  730 , thereby protecting the forward path from distortion by-product signals generated in the reverse path. 
     The foregoing disclosure is not intended to limit the present invention to the precise forms or particular fields of use disclosed. It is contemplated that various alternate embodiments and/or modifications to the present invention, whether explicitly described or implied herein, are possible in light of the disclosure. For example, any number of RF output ports may be supported by the various amplifier embodiments discussed herein.