Switchable highpass filter for catv return path

Abstract

A device for filtering a cable television (CATV) signal includes an input port configured to receive downstream signals from a CATV headend and transmit upstream signals to the CATV headend. The device also includes an output port configured to receive the upstream signals from a subscriber device and transmit the downstream signals to the subscriber device. The device also includes a filter circuit configured to transmit the upstream and the downstream signals between the input port and the output port for a predetermined duration. The predetermined duration starts in response to the output port being coupled to the subscriber device. The filter circuit is configured to block at least a portion of the upstream signals, at least a portion of the downstream signals, or both from being transmitted between the input port and the output port in response to an expiration of the predetermined duration.

What is claimed is: 
     
         1 . A device for filtering a cable television (CATV) signal, the device comprising:
 an input port configured to receive downstream signals from a CATV headend and transmit upstream signals to the CATV headend;   an output port configured to receive the upstream signals from a subscriber device and transmit the downstream signals to the subscriber device; and   a filter circuit configured to transmit the upstream and the downstream signals between the input port and the output port for a predetermined duration, wherein the predetermined duration starts in response to the output port being coupled to the subscriber device, and wherein the filter circuit is configured to block at least a portion of the upstream signals, at least a portion of the downstream signals, or both from being transmitted between the input port and the output port in response to an expiration of the predetermined duration.   
     
     
         2 . The device of  claim 1 , wherein the upstream and downstream signals that are configured to be transmitted during the predetermined duration are in a first frequency band, and wherein the upstream and downstream signals that are configured to be transmitted after the expiration of the predetermined duration are in a second frequency band that is different from the first frequency band. 
     
     
         3 . The device of  claim 1 , further comprising an insulator configured to move from a first position to a second position in response to the output port being coupled to the subscriber device, wherein the predetermined duration starts in response to the insulator moving to the second position. 
     
     
         4 . The device of  claim 3 , further comprising a biasing mechanism configured to bias the insulator into the first position prior to the output port being coupled to the subscriber device. 
     
     
         5 . The device of  claim 3 , further comprising a trigger configured to actuate in response to the insulator moving from the first position to the second position, wherein the predetermined duration starts in response to the trigger being actuated. 
     
     
         6 . A device for filtering a cable television (CATV) signal, the device comprising:
 a switch configured to actuate into a powered state in response to an output port being coupled to a subscriber device, wherein the switch remains in the powered state for a predetermined duration and then actuates into an unpowered state after the predetermined duration; and   a filter circuit configured to relay two-way CATV signals between an input port and the output port when the switch is in the powered state, and block at least a portion of the two-way CATV signals from being relayed between the input port and the output port when the switch is in the unpowered state.   
     
     
         7 . The device of  claim 6 , wherein the two-way CATV signals comprise upstream signals and downstream signals, and wherein the input port is configured to relay the upstream signals to a CATV headend and the downstream signals from the CATV headend. 
     
     
         8 . The device of  claim 6 , wherein the two-way CATV signals comprise downstream signals, and wherein the output port is configured to relay the downstream signals to the subscriber device. 
     
     
         9 . The device of  claim 6 , wherein the two-way CATV signals comprise downstream CATV signals. 
     
     
         10 . The device of  claim 6 , wherein the two-way CATV signals comprise upstream CATV signals. 
     
     
         11 . The device of  claim 6 , wherein the two-way CATV signals comprise downstream and upstream CATV signals. 
     
     
         12 . The device of  claim 6 , wherein the portion of the two-way CATV signals comprises a downstream portion of CATV signals. 
     
     
         13 . The device of  claim 6 , wherein the portion of the two-way CATV signals comprises an upstream portion of CATV signals. 
     
     
         14 . The device of  claim 6 , wherein the two-way CATV signals that are configured to be relayed during the predetermined duration are in a first frequency band, and wherein the two-way CATV signals that are configured to be relayed after the expiration of the predetermined duration are in a second frequency band that is different from the first frequency band. 
     
     
         15 . The device of  claim 6 , wherein the switch comprises a first switch coupled to a first side of the filter circuit and a second switch coupled to a second side of the filter circuit, wherein the first and second switches are configured to actuate simultaneously between the powered state and the unpowered state. 
     
     
         16 . The device of  claim 6 , further comprising a trigger that is configured to actuate in response to the output port being coupled to the subscriber device, wherein the switch is configured to actuate into the powered state for the predetermined duration in response to actuation of the trigger. 
     
     
         17 . The device of  claim 16 , further comprising a power circuit comprising a battery, wherein the power circuit is configured to supply power from the battery to the switch for the predetermined duration in response to actuation of the trigger, causing the switch to remain in the powered state for the predetermined duration. 
     
     
         18 . The device of  claim 17 , wherein the battery fails to supply a threshold current to the switch after the predetermined duration, causing the switch to actuate into the unpowered state. 
     
     
         19 . The device of  claim 17 , wherein the power circuit comprises a power circuit switch configured to actuate from an open state to a closed state in response to actuation of the trigger, causing the battery to supply power to the switch. 
     
     
         20 . A device for filtering a cable television (CATV) signal, the device comprising:
 a housing;   an insulator configured to be pressed at least partially into the housing in response to an output port being physically coupled to a subscriber device;   a switch configured to actuate from a first state into a second state in response to the insulator being pressed at least partially into the housing, wherein the switch remains in the second state for a predetermined duration and then actuates back into the first state after the predetermined duration; and   a filter circuit configured to relay CATV signals between an input port and the output port when the switch is in the second state, and block at least a portion of the CATV signals from being relayed between the input port and the output port when the switch is in the first state.