NxM crosspoint switch with band translation

Abstract

An N×M crosspoint switch allows a signal from any one of the N inputs to be routed to one or more of the M crosspoint switch outputs. The switches within the crosspoint switch can be configured as voltage mode or current mode switches. In voltage mode switching an input to the crosspoint switch is provided to an input device, such as an amplifier, having a low output impedance. The output of the low impedance device is provided to a switch that connects the output of the low impedance device to a high input impedance device, such as a band translation device. In current mode switching, the low impedance output of the input device is connected to selectively activated high isolation transconductance devices having high input impedances. The outputs of the transconductance devices are connected to low impedance devices that operate as summing nodes.

1 . An integrated circuit, having N-input by M-output crosspoint switch with band translation, for use in an RF signal distribution system, the integrated circuit comprising: 
 an N input switch configured to route an input signal at any one of the N inputs to any one of the M outputs, with each of the N inputs having a high input impedance; and    M band translation devices, each of the M band translation devices connected to an output of the N input switch and configured to selectively frequency translate or pass through a signal from the output of the N input switch.    
   
   
       2 . The integrated circuit of  claim 1 , wherein the N input switch comprises N groups of M switches, with each group of M switches having inputs connected to a separate one of the N inputs, each group of M switches further having each of the M switch outputs connected to a separate one of the M band translation devices.  
   
   
       3 . The integrated circuit of  claim 2 , wherein each switch in the N groups of M switches comprises a voltage mode switch and wherein each of the band translation devices has a high impedance input.  
   
   
       4 . The integrated circuit of  claim 2 , wherein each switch in the N groups of M switches comprises a current mode switch and wherein each of the band translation devices has a low impedance input.  
   
   
       5 . The integrated circuit of  claim 2 , wherein each switch in the N groups of M switches comprises a transconductance device.  
   
   
       6 . The integrated circuit of  claim 2 , wherein each switch in the N groups of M switches is selectively enabled or disabled based on a control signal.  
   
   
       7 . The integrated circuit of  claim 2 , wherein each switch in the N groups of M switches provides greater than 30 dB of signal isolation in a disabled state.  
   
   
       8 . The integrated circuit of  claim 1 , further comprising N low noise amplifiers (LNAs), with each LNA having an output connected to a separate input on the N input switch.  
   
   
       9 . The integrated circuit of  claim 1 , wherein the N input switch and the M band translation devices include differential signal inputs and differential signal outputs.  
   
   
       10 . The integrated circuit of  claim 1 , wherein each of the M band translation devices is configured to frequency translate a signal from a first RF frequency band to a second RF frequency band.  
   
   
       11 . An integrated circuit having a crosspoint switch with band translation for use in an RF signal distribution system, the integrated circuit comprising: 
 a first low noise amplifier (LNA) having a differential input and a low impedance differential output;    a first transconductance device having a differential output and a high impedance differential input connected to the low impedance differential output of the first LNA;    a second transconductance device having a differential output and a high impedance differential input connected to the low impedance differential output of the first LNA;    a first band translation device having a differential output and a low impedance differential input connected to the differential output of the first transconductance device; and    a second band translation device having a differential output and a low impedance differential input connected to the differential output of the second transconductance device.    
   
   
       12 . The integrated circuit of  claim 11 , wherein the first transconductance device comprises a controllable current source configured to selectively enable and disable the first transconductance device.  
   
   
       13 . A method of routing signals in a reconfigurable signal distribution system, the method comprising: 
 receiving a signal at a matched impedance input of a low noise amplifier (LNA) having a low output impedance;    selectively routing an output voltage of the LNA, using a first transconductance device having a high impedance input, as a current at an output of the first transconductance device;    selectively routing an output voltage of the LNA, using a second transconductance device having a high impedance input, as a current at an output of the second transconductance device; and    frequency translating a signal at the output of the first transconductance device from a first RF frequency band to a second RF frequency band.    
   
   
       14 . A method of routing signals in a reconfigurable signal distribution system, the method comprising: 
 receiving an input signal at a matched impedance input of a input device;    generating an intermediate signal, based in part on the input signal, at the low impedance output of the input device;    providing the intermediate signal to a high impedance input of a current source;    selectively enabling the current source to provide an output current signal based in part on the intermediate signal;    receiving the output current signal at a low impedance input of a band translation device; and    frequency translating the output current signal from a first frequency band to a second frequency band.