Amplifier with noise reduction

Abstract

The present invention helps eliminate ingress noise addition (i.e., the “noise funneling effect” for an HFC coaxial plant). A system according to various aspects of the present invention comprises a switch that includes: (i) a first state for allowing passage of a signal therethrough; and (ii) a second state for preventing passage of the signal therethrough. The system further includes a detection circuit in communication with the switch. The detection circuit is configured to: (i) detect whether the signal includes an amplitude of at least a predetermined level; (ii) operate the switch to the first state if the amplitude of the signal is at least the predetermined level; and (iii) operate the switch to the second state if the amplitude of the signal is less than the predetermined level, wherein operation of the switch to the second state is delayed by a predetermined period of time.

What is claimed is: 
     
         1 . A system comprising:
 (a) a switch including:
 (i) a first state for allowing passage of a signal therethrough; and 
 (ii) a second state for preventing passage of the signal therethrough; and 
   (b) a detection circuit in communication with the switch, the detection circuit configured to:
 (i) detect whether the signal includes an amplitude of at east a predetermined level; 
 (ii) operate the switch to the first state if the amplitude of the signal is at least the predetermined level; and 
 (iii) operate the switch to the second state if the amplitude of the signal is less than the predetermined level, wherein operation of the switch to the second state is delayed by a predetermined period of time. 
   
     
     
         2 . The system of  claim 1 , wherein the detection circuit comprises a radio frequency detector for detecting the amplitude of the signal. 
     
     
         3 . The system of  claim 2 , wherein the detection circuit further comprises an amplifier in communication with the radio frequency detector, the amplifier for amplifying the signal. 
     
     
         4 . The system of  claim 2 , wherein the detection circuit further comprises a timing circuit in communication with the radio frequency detector, the timing circuit configured to delay, by the predetermined period of time, operation of the switch to the second state. 
     
     
         5 . The system of  claim 1 , wherein the predetermined period of time is selected to avoid a loss of data due to a premature operation of the switch to the second state. 
     
     
         6 . The system of  claim 1 , wherein the switch includes one or more of:
 a radio frequency gate;   a radio frequency switch;   a voltage-controlled variable attenuator; and   combinations thereof.   
     
     
         7 . The system of  claim 1 , wherein the signal is a return signal, the system further comprising:
 (a) a first interface for receiving a forward signal and providing the return signal; and   (b) a second interface for providing the forward signal and receiving the return signal.   
     
     
         8 . The system of  claim 7 , further comprising a first diplex filter coupled to the first interface, the first diplex filter including:
 (a) a forward signal port; and   (b) a return signal port in communication with the switch.   
     
     
         9 . The system of  claim 8 , further comprising a second diplex filter coupled to the second interface, the second diplex filter including:
 (a) a forward signal port; and   (b) a return signal port in communication with the switch.   
     
     
         10 . The system of  claim 9 , further comprising a forward signal amplifier coupled to the forward signal port of the first dip ex filter and the forward signal port of the second diplex filter. 
     
     
         11 . The system of  claim 9 , further comprising a return signal amplifier coupled to the return signal port of the first diplex filter and the switch. 
     
     
         12 . The system of  claim 9 , further comprising:
 (a) a plurality of second interfaces;   (b) a radio frequency sputter coupled to the second diplex filter, the radio frequency splitter including a port coupled to a respective one of each of the plurality of second interfaces.   
     
     
         13 . The system of  claim 12 , further comprising:
 (a) a second radio frequency splitter coupled to the first interface, the second radio frequency splitter including:
 (i) a first port coupled to the first diplex filter; and 
 (ii) a second port coupled to one or more of the second interfaces.