Four-way four-wire active bridge

Claim 2

An active four port bridge comprising: a. first, second, third, and fourth distribution amplifier means, each of said distribution amplifier means adapted to receive an input signal; and b. first, second, third and fourth summing amplifier means, each of said summing amplifier means adapted to transmit an output signal related to said input signal, one of said distribution amplifier means and one of said summing amplifier means coupled to each port for transmitting and receiving signals; c. said first distribution amplifier means connected only to said second, third, and fourth summing amplifier means; d. said second distribution amplifier means connected only to said first, third, and fourth summing amplifier means; e. said third distribution amplifier means connected only to said first, second and fourth summing amplifier means; f. said fourth distribution amplifier means connected only to said first, second, and third summing amplifier means; g. said first summing amplifier means operative to sum signals from said second, third and fourth distribution amplifier means, said second summing amplifier means operative to sum signals from said first, third and fourth distribution amplifier means, said third summing amplifier means operative to sum signals from said first, second and fourth distribution amplifier means, said fourth summing amplifier means operative to sum signals from said first, second and third distribution amplifier means; h. said input signal applied to one of said distribution amplifier means is fed only to said summing amplifier means operatively connected to said distribution amplifier means to which said input signal is applied.

Claim 3

The active bridge as claimed in claim 1 wherein said first distribution amplifier means and said first summing amplifier means define first port means, said second distribution amplifier means and said second summing amplifier means define second port means, said third distribution amplifier means and said third summing amplifier means define third port means, and said fourth distribution amplifier means and said fourth distribution amplifier means define fourth port means, said distribution amplifier means and said summing amplifier means of each said port means being electrically isolated from each other, said input signal received at one of said ports is applied only to the other ones of said ports.

Claim 4

The active bridge as claimed in claim 1 wherein each of said distribution amplifier means includes a differential input operational amplifier having first and second input terminals and an output terminal.

Claim 5

The active bridge as claimed in claim 3 including first, second, third, and fourth transformer means, each of said transformer means having first and second windings, said first winding of said first tranformer means connected between said first and second input terminals of said first distribution amplifier means, an input signal applied to said second winding of said first transformer means coupled to said first distribution amplifier means through said first winding of said first transformer means, said first winding of said second transformer means connected between said first and second input terminals of said second distribution amplifier means, an input signal apPlied to said second winding of said second transformer means coupled to said second distribution amplifier means through said first winding of said second transformer means, said first winding of said third transformer means connected between said first and second input terminals of said third distribution amplifier means, an input signal applied to said second winding of said third transfromer means coupled to said third distribution amplifier means through said first winding of said third transformer means, and said first winding of said fourth transformer means connected between said first and second input terminals of said fourth distribution amplifier means, an input signal applied to said second winding of said fourth transformer means coupled to said fourth distribution amplifier means through said first winding of said fourth transformer means, a terminating resistor defining an input impedance being connected across said first winding of each said transformer means.

Claim 6

The active bridge as claimed in claim 1 wherein each of said summing amplifier means includes a differential input operational amplifier having first and second input terminals and an output terminal.

Claim 7

The active bridge as claimed in claim 5 including first, second, third, and fourth transformer means, each of said transformer means having first and second windings, said first winding of said first transformer means is connected between said second input terminal and said output terminal of said first summing amplifier means, a signal at said output terminal of said first summing amplifier means is applied to said first winding of said first transformer means and is coupled to said second winding of said first transformer means, said first winding of said second transformer means is connected between said second input terminal and said output terminal of said second summing amplifier means, a signal at said output terminal of said second summing amplifier means is applied to said first winding of said second transformer means and is coupled to said second winding of said second transformer means, said first winding of said third transformer means is connected between said second input terminal and said output terminal of said third summing amplifier means, a signal at said output terminal of said third summing amplifier means is applied to said first winding of said third transformer means and is coupled to said second winding of said third transformer means, said first winding of said fourth transfromer menas is connected between said second input terminal and said output terminal of said fourth summing amplifier means, a signal at said output terminal of said fourth summing amplifier means is applied to said first winding of said fourth transformer means and is coupled to said second winding of said fourth transformer means.

Claim 8

An active four port bridge comprising: a. first port means including input means for receiving a signal and output means for summing and for transmitting a signal, said first port means input means electrically isolated from said first port means output means; b. second port means including input means for receiving a signal and output means for summing and for transmitting a signal, said second port means input means electically isoloated from said second port means output means; c. third port means including input means for receiving a signal and output means for summing and for transmitting a signal, said third port means input means electically isolated from said third port means output means; and d. fourth port means including input means for receiving a signal and output means for summing and for transmitting a signal, said fourth port means input means electrically isolated from said fourth port means output means; e. said first port means input means connected only to said second, third, and fourth port means outport means; f. said second port input means connected only to said first, third, and fourth port means output means; g. said third port means input means connectedd only to said first, second, and fourth port means output means; h. said fourth port means input means connected only to said first, second, and third port means output means; i. a signal received at said first port means input means is applied to said second, third, and fourth port means output means, said signal at said second, third, and fourth port means output means from said first port means input means having a magnitude at least equal to the magnitude of said signal received at said first port means input means; j. a signal received at said second port means input means is applied to said first, third and fourth port means output means, said signal at said first; third, and fourth port means output means from said second port means input means having a magnitude at least equal to the magnitude of said signal received at said second port means input means; k. a signal received at said third port means imput means is applied to said first, second and fourth port means output means, said signal at said first, second, and fourth port means output means from said third port means input means having a magnitude at least equal to the magnitude of said signal received at said third port means input means; l. a signal received at said fourth port means input means is applied to said first, second, and third port means output means, said signal at said first, second, and third port means output means from said fourth port means input means having a magnitude at least equal to the magnitude of said signal received at said fourth port means input means; m. said first port means output means operative to sum signals from said second, third and fourth port means input means, said second port means output means operative to sum signals from said first, third and fourth port means input means, said third port means output means operative to sum signals from said first, second and fourth port means input means, said fourth port means output means operative to sum signals from said first, second and third port means input means.

Claim 9

An active four port bridge comprising: a. first port means including input means for receiving a signal and output means for summing and for transmitting a signal, said first port means input means electrically isolated from said first port means output means; b. second port means including input means for receiving a signal and output means for summing and for transmitting a signal, said second port means input means electically isoloated from said second port means output means; c. third port means including input means for receiving a signal and output means for summing and for transmitting a signal, said third port means input means electically isolated from said third port means output means; and d. fourth port means including input means for receiving a signal and output means for summing and for transmitting a signal, said fourth port means input means electrically isolated from said fourth port means output means; e. said first port means input means connected only to said second, third, and fourth port means outport means; f. said second port input means connected only to said first, third, and fourth port means output means; g. said third port means input means connectedd only to said first, second, and fourth port means output means; h. said fourth port means input means connected only to said first, second, and third port means output means; i. a signal received at said first port means input means is applied to said second, third, and fourth port means output means, said signal at said second, third, and fourth port means output means from said first port means input means having a magnitude at least equal to the magnitude of said signal received at said first port means input means; j. a signal received at said second port means input means is applied to said first, third and fourth port means output means, said signal at said first; third, and fourth port means output means from said second port means input means having a magnitude at least equal to the magnitude of said signal received at said second port means input means; k. a signal received at said third port means imput means is applied to said first, second and fourth port means output means, said signal at said first, second, and fourth port means output means from said third port means input means having a magnitude at least equal to the magnitude of said signal received at said third port means input means; l. a signal received at said fourth port means input means is applied to said first, second, and third port means output means, said signal at said first, second, and third port means output means from said fourth port means input means having a magnitude at least equal to the magnitude of said signal received at said fourth port means input means; m. said first port means output means operative to sum signals from said second, third and fourth port means input means, said second port means output means operative to sum signals from said first, third and fourth port means input means, said third port means output means operative to sum signals from said first, second and fourth port means input means, said fourth port means output means operative to sum signals from said first, second and third port means input means.

Claim 10

The active bridge as claimed in claim 7 wherein each said input means includes distribution amplifier means, each said distribution amplifier means having first and second input terminals and an output terminal.

Claim 11

The active bridge as claimed in claim 8 including first, second, third, and fourth transformer means, each of said transformer means having first and second windings, said first winding of said first transformer means connected between said first and second input terminals of said distribution amplifier means of said first port means input means, an input signal applied to said second winding of said first transformer means coupled to said distribution amplifier amplifier means of said first port means input means through said first winding of said first transformer means, said first winding of said second transformer means connected between said first and second input terminals of said distribution amplifier means of said second port means input means, an input signal applied to said second winding of said second transfromer means coupled to said distribution amplifier means of said second port means input means through said first winding of said second transformer means, said first winding of said third transformer means connected between said first and second input terminals of said distribution amplifier means of said third port means input means, an input signal applied to said second winding of said third transformer means coupled to said distribution amplifier means of said third port means input means through said first winding of said third transformer means, and said first winding of said fourth transformer means connected between said first and second input terminals of said distribution amplifier means of said fourth port means input means, an input signal applied to said second winding of said fourth transformer means coupled to saiD distribution amplifier means of said fourth port means input means through said first winding of said fourth transformer means, a terminating resistor defining an input impedance being connected across said first winding of each said transformer means.

Claim 12

The active bridge as claimed in claim 7 wherein each said output means includes summing amplifier means having first and second input terminals and an output terminal.

Claim 13

The active bridge as claimed in claim 10 including first, second, third, and fourth transformer means, each of said transformer means having first and second windings, said first winding of said first transformer means is connected between said second input termianl and said output terminal of said summing amplifier means of said first port means output means output means, a signal at said output terminal of said summing amplifier means of said first port means output means is applied to said first winding of said first transformer means and is coupled to said second winding of said first transformer means, said first winding of said second transformer means is connected between said second input terminal and said output terminal of said summing amplifier means of said second port means output means, a signal at said output terminal of said summing amplifier means of said second port means output means is applied to said first winding of said second transformer means and is coupled to said second winding of said second transformer means, said first winding of said third transformer means is connected between said second input terminal and said output terminal of said summing amplifier means of said third port means output means, a signal at said output terminal of said summing amplifier means of said third port means output means is applied to said first winding of said third transformer means and is coupled to said second winding of said third transformer means, said first winding of said fourth transformer means is connected between said second input terminal and said output terminal of said summing amplifier means of said fourth port means output means, a signal at said output terminal of said summing amplifier means of said fourth port means output means is applied to said first winding of said fourth transformer means and is coupled to said second winding of said fourth transformer means.