Shifting phase in a television camera

Claim 2

A phase shifting device comprising: a pair of transistor phase modulator circuits, each of said modulator circuits including two transistors and having the collectors of the transistors in each of the modulator circuits connected to the collectors of the corresponding transistors in the other modulator circuit: means applying square wave biasing signals to the base of each of the transistors in said pair of modulator circuits in a manner such that the phase of said square wave signal applied to each of said transistors is 180* out of phase with the square wave signal applied to the other transistor in the same modulator circuit and in quadrature with the square wave signals applied to either of the transistors in the other modulator circuit; a bridge-type input circuit connected to supply input signals to said pair of phase modulator circuits and serving to vary the ratios of said input signals in response to variations in the circuit input signal; and differential input means supplying a circuit input signal to said bridge-type input circuit.

Claim 3

The device of claim 1 wherein said bridge-type circuit is a transistor bridge circuit comprises: first, second, third, and fourth transistors; a first resistOr connecting the emitters of said first and second transisto;: means connecting the emitter of said first transistor to the collector of said third transistor; means connecting the emitter of said second transistor to the collector of said fourth transistor; a first biasing source connected to the bases of said third and fourth transistors; a second biasing source; a pair of identical resistors each connecting said second biasing source to the emitter of a respective one of said third and fourth transistors; and differential input means connected to the bases of said first and second transistors.

Claim 4

A phase shifting device comprising: a pair of transistor phase modulator circuits having the collectors of the transistors in each of the modulator circuits connected to the collectors of the corresponding transistors in the other modulator circuit; means applying square wave biasing signals to the base of each of the transistors in said pair of modulator circuits in a manner such that the phase of said square wave signal applied to each of said transistors is 180* out of phase with the square wave signal applied to the other transistor in the same modulator circuit and in quadrature with the square wave signals applied to either of the transistors in the other modulator circuit; a bridge-type input circuit connected to supply input signals to said pair of phase modulator circuits and serving to vary the ratios of said input signals in response to variations in the circuit input signal, said bridge-type circuit comprising: first, second, third, and fourth transistors; a first resistor connecting the emitters of said first and second transistor; means connecting the emitter of said first transistor to the collector of said third transistor; means connecting the emitter of said second transistor to the collector of said fourth transistor; a first biasing source connected to the bases of said third and fourth transistors: a second biasing source; a pair of identical resistors each connecting said second biasing source to the emitter of a respective one of said third and fourth transistors; and differential input means connected to the bases of said first and second transistors.

Claim 5

A phase shifting device comprising: a pair of transistor phase modulator circuits having the collectors of the transistors in each of the modulator circuits connected to the collectors of the corresponding transistors in the other modulator circuit; means applying square wave biasing signals to the base of each of the transistors in said pair of modulator circuits in a manner such that the phase of said square wave signal applied to each of said transistors is 180* out of phase with the square wave signal applied to the other transistor in the same modulator circuit and in quadrature with the square wave signals applied to either of the transistors in the other modulator circuit; a bridge-type input circuit connected to supply input signals to said pair of phase modulator circuits and serving to vary the ratios of said input signals in response to variations in the circuit input signal, said bridge-type circuit comprising: first, second, third, and fourth transistors; a first resistor connecting the emitters of said first and second transistor; means connecting the emitter of said first transistor to the collector of said third transistor; means connecting the emitter of said second transistor to the collector of said fourth transistor; a first biasing source connected to the bases of said third and fourth transistors: a second biasing source; a pair of identical resistors each connecting said second biasing source to the emitter of a respective one of said third and fourth transistors; and differential input means connected to the bases of said first and second transistors.

Claim 6

The device of claim 3 wherein: said collectors are connected in a parallel summing relation; and a respective output means is connected to receive summed currents from each pair of collector-connected transistors.

Claim 7

The device of claim 3 wherein: the value of the circuit input signal supplied by said differential input means is equal to the voltage drop across said pair of identical resistors multiplied by the number of degrees of phase shift desired.