Phase shift circuits

Claim 2

Apparatus for varying the phase angle of a signal comprising, a. an amplifier circuit including first and second active devices having input, output, and common electrodes, said common electrodes coupled together and returned to a point of reference potential, b. means coupled to at lEast one of said input electrodes for applying said signal thereto, to provide at said output electrodes replicas of said signal of a different phase with respect to one another, c. means coupled to said output electrode of said first active device for providing first and second controllable current paths, said current through said first and second paths approximately equal to the total current through said first active device, d. means coupling the output electrode of said second active device to said first current path for applying said replica of said signal of said different phase thereto, and e. means coupled to said second controllable path for varying said second current for determining the division of said first and second currents as formulating said total current, and f. means coupled to said first current path responsive to said current flowing therethrough for providing a signal having a phase determined in accordance with said division.

Claim 3

Apparatus for varying the phase of a signal comprising, a. first and second transistors arranged in a differential amplifier configuration having the emitter electrodes thereof coupled together and returned to a point of reference potential, b. first means coupled to at least one of the base electrodes of said transistors for applying said signal thereto, to provide at each of said collector electrodes a replica of said signal and of a different phase with respect to one another, c. second means coupled to the collector electrode of said first transistor for shifting the phase of said signal appearing thereat by a predetermined amount, d. third means coupled to the collector electrode of said second transistor for providing first and second controllable current paths wherein each path as controlled serves with the other to direct current through the collector to emitter path of said second transistor, said current through said first and second paths being approximately equal to the total current through said second transistor including that current due to said signal applied to said base electrode, e. fourth means coupling said second means to said first controllable current path for applying at least a portion of said phase-shifted signal thereto, f. fifth means coupled to said second controllable current path for determining that portion of the total current supplied by said second current path and therefore by said first path, g. means coupled to said first controllable current path responsive to said current flowing therein to provide a signal having a phase determined in accordance with that portion of the total current supplied to said first path.

Claim 4

Apparatus for varying the phase of a signal comprising, a. first and second transistors arranged in a differential amplifier configuration having the emitter electrodes thereof coupled together and returned to a point of reference potential, b. first means coupled to at least one of the base electrodes of said transistors for applying said signal thereto, to provide at each of said collector electrodes a replica of said signal and of a different phase with respect to one another, c. second means coupled to the collector electrode of said first transistor for shifting the phase of said signal appearing thereat by a predetermined amount, d. third means coupled to the collector electrode of said second transistor for providing first and second controllable current paths wherein each path as controlled serves with the other to direct current through the collector to emitter path of said second transistor, said current through said first and second paths being approximately equal to the total current through said second transistor including that current due to said signal applied to said base electrode, e. fourth means coupling said second means to said first controllable current path for applying at least a portion of said phase-shifted signal thereto, f. fifth means coupled to said second controllable current path for determining that portion of the total current supplied by said second current path and therefore by said first path, g. means coupled to said first controllable current path responsive to said current flowing therein to provide a signal having a phase determined in accordance with that portion of the total current supplied to said first path.

Claim 5

Apparatus for varying the phase of a signal comprising, a. first and second transistors arranged in a differential amplifier configuration having the emitter electrodes thereof coupled together and returned to a point of reference potential, b. first means coupled to at least one of the base electrodes of said transistors for applying said signal thereto, to provide at each of said collector electrodes a replica of said signal of a different phase with respect to one another, c. second means coupled to the collector electrode of said first transistor for providing first and second controllable current paths wherein each path as controlled serves with the other to direct current through the collector to emitter path of said first transistor, said current through said first and second paths being equal to the total current through said first transistor including that current due to said signal applied to said base electrode, d. third means coupling said collector electrode of said second transistor to said first controllable current path of said second means for applying at least a portion of said different phase signal thereto, e. fourth means coupled to said controllable current path for determining that portion of the total current supplied by said second current path and therefore by said first path, and f. means coupled to said first current path to provide a voltage thereacross having a phase angle determined by the amount of current flowing through said first path.

Claim 6

Apparatus for varying the phase of a signal comprising, a. first and second transistors arranged in a differential amplifier configuration having the emitter electrodes thereof coupled together and returned to a point of reference potential, b. first means coupled to at least one of the base electrodes of said transistors for applying said signal thereto, to provide at each of said collector electrodes a replica of said signal of a different phase with respect to one another, c. second means coupled to the collector electrode of said first transistor for providing first and second controllable current paths wherein each path as controlled serves with the other to direct current through the collector to emitter path of said first transistor, said current through said first and second paths being equal to the total current through said first transistor including that current due to said signal applied to said base electrode, d. third means coupling said collector electrode of said second transistor to said first controllable current path of said second means for applying at least a portion of said different phase signal thereto, e. fourth means coupled to said controllable current path for determining that portion of the total current supplied by said second current path and therefore by said first path, and f. means coupled to said first current path to provide a voltage thereacross having a phase angle determined by the amount of current flowing through said first path.

Claim 7

The apparatus according to claim 3 wherein said second means coupled to the collector electrode of said first transistor providing said first controllable current path comprises, a. a third transistor having a base, collector and emitter electrode, said emitter electrode coupled to said collector electrode of said first transistor, b. means for biasing said base electrode, c. means coupling said collector electrode of said third transistor to a point of operating potential, d. means coupled to said emitter electrode for varying the bias between said base and emitter electrodes and therefore varying said current through said first path.

Claim 8

The apparatus according to claim 3 wherein said second means coupled to the collector of said transistor providing said second controllable current path comprises, a. a unilateral current conducting device having a first and a second terminals and poled to conduct current from said first to said second terminal, said second terminal coupled to the emitter electrode of said third transistor b. a variable resistor coupled between said first terminal of said unilateral conducting device and a point of operating potential for varying the current conducted by said device according to the variation in magnitude of said resistor.

Claim 9

Apparatus for changing the phase of a signal of a predetermined frequency, comprising, a. a differential amplifier, including first and second transistors each having a base, collector, and emitter electrode, said emitter electrodes being coupled one to another, b. means coupled to at least one of said base electrodes for applying said signal thereto, to provide an amplified signal at said collector electrodes, c. a third transistor having a collector electrode coupled to said emitter electrodes of said first and second transistors and an emitter electrode returned to a point of reference potential, d. means coupled to the base electrode of said third transistor for biasing said transistor to conduct current via said collector to emitter path of a magnitude approximately equal to the current flowing through said collector to emitter paths of said first and second transistors, e. a phase shifting network coupled to the collector electrode of said first transistor for providing a given phase shift to said signal appearing at said collector electrode, f. means coupling said phase shifting network to the collector electrode of said second transistor for application of a portion of said given phase shifted signal thereto, to cause said phase shifted signal as applied to said collector electrode to vectorially add with respect to that signal present due to said signal applied to said base electrode, for providing a changed phase shifted signal at said collector electrode of said second transistor.

Claim 10

Apparatus for changing the phase of a signal of a predetermined frequency, comprising, a. a differential amplifier, including first and second transistors each having a base, collector, and emitter electrode, said emitter electrodes being coupled one to another, b. means coupled to at least one of said base electrodes for applying said signal thereto, to provide an amplified signal at said collector electrodes, c. a third transistor having a collector electrode coupled to said emitter electrodes of said first and second transistors and an emitter electrode returned to a point of reference potential, d. means coupled to the base electrode of said third transistor for biasing said transistor to conduct current via said collector to emitter path of a magnitude approximately equal to the current flowing through said collector to emitter paths of said first and second transistors, e. a phase shifting network coupled to the collector electrode of said first transistor for providing a given phase shift to said signal appearing at said collector electrode, f. means coupling said phase shifting network to the collector electrode of said second transistor for application of a portion of said given phase shifted signal thereto, to cause said phase shifted signal as applied to said collector electrode to vectorially add with respect to that signal present due to said signal applied to said base electrode, for providing a changed phase shifted signal at said collector electrode of said second transistor.

Claim 11

The apparatus according to claim 6 wherein said means coupled to the base electrode of said third transistor includes, a. a unilateral current conducting device coupled between the base electrode of said transistor and a point of reference potential and poled for easy current conduction in the same direction as said base to emitter junction of said transistor, and b. a resistor coupled between said base electrode and a point of operating potential.

Claim 12

The apparatus according to claim 7 wherein said phase shifting network comprises, a. a resistor coupled between said collector of said first transistor and said point of operating potential, b. a capacitor in parallel with said resistor for providing said given phase shift to said signal appearing at said collector electrode.

Claim 13

In combination: a. first and second transistors arranged in a differential amplifier configuration, having the emitter electrodes coupled together, b. means coupLed to said emitter electrodes for biasing said transistors for current conduction of a magnitude equal to a predetermined value which value is substantially the same for all signal conditions, whereby if the current through one of said transistors increases the current through said other transistor decreases to maintain said predetermined value relatively constant, c. a terminal adapted for application thereto of an operating potential, d. impedance means coupled between the collector electrode of said first transistor and said first terminal, e. a third transistor having a collector electrode coupled to said first terminal and a base electrode coupled to said impedance means, f. means coupling the emitter electrode of said third transistor to the collector electrode of said second transistor to form a first current path for said second transistor, g. a unidirectional current conducting device poled for current conduction between a first an second electrode in the same direction as said base to emitter junction of said third transistor, said second electrode being coupled to said collector electrode of said second transistor to form a second current path for said second transistor, h. variable impedance means coupled between said first electrode of said unidirectional current conducting device and said first terminal for varying the current flowing through said device and therefore through said first and second electrodes, said means thereby serving to determine that portion of current flowing through said second current path and therefore through said first current path, i. means coupled to the base electrodes of said first and second transistors for application of a signal thereto to cause the signal developed at the collector electrode of said first transistor to be applied to the base electrode of said third transistor for applying a current through said third transistor and therefore through said first current path; whereby the total current supplied by said second transistor as necessary to maintain said predetermined current value relatively constant is provided by said first and second current paths proportioned to conduct current according to the variation of said variable impedance means.

Claim 14

In combination: a. first and second transistors arranged in a differential amplifier configuration, having the emitter electrodes coupled together, b. means coupLed to said emitter electrodes for biasing said transistors for current conduction of a magnitude equal to a predetermined value which value is substantially the same for all signal conditions, whereby if the current through one of said transistors increases the current through said other transistor decreases to maintain said predetermined value relatively constant, c. a terminal adapted for application thereto of an operating potential, d. impedance means coupled between the collector electrode of said first transistor and said first terminal, e. a third transistor having a collector electrode coupled to said first terminal and a base electrode coupled to said impedance means, f. means coupling the emitter electrode of said third transistor to the collector electrode of said second transistor to form a first current path for said second transistor, g. a unidirectional current conducting device poled for current conduction between a first an second electrode in the same direction as said base to emitter junction of said third transistor, said second electrode being coupled to said collector electrode of said second transistor to form a second current path for said second transistor, h. variable impedance means coupled between said first electrode of said unidirectional current conducting device and said first terminal for varying the current flowing through said device and therefore through said first and second electrodes, said means thereby serving to determine that portion of current flowing through said second current path and therefore through said first current path, i. means coupled to the base electrodes of said first and second transistors for application of a signal thereto to cause the signal developed at the collector electrode of said first transistor to be applied to the base electrode of said third transistor for applying a current through said third transistor and therefore through said first current path; whereby the total current supplied by said second transistor as necessary to maintain said predetermined current value relatively constant is provided by said first and second current paths proportioned to conduct current according to the variation of said variable impedance means.

Claim 15

The combination according to claim 9 wherein said means coupled to said emitter electrodes of said first and second transistors comprises a. a fourth transistor having a collector electrode coupled to said emitter electrodes of said first and second transistors and an emitter electrode coupled to a point of reference potential, b. a unidirectional current device coupled between said base electrode of said fourth transistor and said point of reference potential, and poled for easy current conduction in the same direction as is said base to emitter electrode of said fourth transistor, c. means including at least one resistor coupling said base electrode of said fourth transistor to said terminal to cause said fourth transistor to conduct current via said collector to emitter path relatively equal to said predetermined value.

Claim 16

The combination according to claim 9 wherein said unidirectional current conducting device is a transistor having a base, collector and emitter electrode, and having each base electrode directly connected to said collector electrode, said collector to base connection being said first electrode and said emitter electrode being said second electrode,

Claim 17

The combination according to claim 11 wherein said variable impedance means comprises, a potentiometer coupled between said first terminal and said first electrode of said collector to base connected transistor.

Claim 18

Apparatus for varying the phase of a signal of a predetermined frequency comprising, a. a differential amplifier, including first and second transistors each having a base, collector, and emitter electrode, said emitter electrodes being coupled on to another, b. means coupled to at least one of said base electrodes for appLying said signal thereto, to provide an amplified signal at said collector electrodes, c. a third transistor having a collector electrode coupled to said emitter electrodes of said first and second transistors and an emitter electrode returned to a point of reference potential, d. means coupled to the base electrode of said third transistor for biasing said transistor to conduct current via said collector to emitter path of a magnitude approximately equal to the current flowing through said collector to emitter paths of said first and second transistors, e. a phase shifting network coupled to the collector electrode of said first transistor for providing a given phase shift to said signal appearing at said collector electrode, f. means coupling said phase shifting network to the collector electrode of said second transistor for application of a portion of said given phase shifted signal thereto, to cause said phase shifted signal as applied to said collector electrode to vectorially add with respect to that signal present due to said signal applied to said base electrode, for providing a changed phase shifted signal at said collector electrode of said second transistor. g. means coupled to the collector electrode of said second transistor for determining the magnitude of said signal to be vectorially added due to said signal applied to said base electrode, for providing said changed phase shifted signal at said collector electrode of said second transistor of changed phase determined in accordance with the magnitude of said signal.

Claim 19

Apparatus for varying the phase of a signal of a predetermined frequency comprising, a. a differential amplifier, including first and second transistors each having a base, collector, and emitter electrode, said emitter electrodes being coupled on to another, b. means coupled to at least one of said base electrodes for appLying said signal thereto, to provide an amplified signal at said collector electrodes, c. a third transistor having a collector electrode coupled to said emitter electrodes of said first and second transistors and an emitter electrode returned to a point of reference potential, d. means coupled to the base electrode of said third transistor for biasing said transistor to conduct current via said collector to emitter path of a magnitude approximately equal to the current flowing through said collector to emitter paths of said first and second transistors, e. a phase shifting network coupled to the collector electrode of said first transistor for providing a given phase shift to said signal appearing at said collector electrode, f. means coupling said phase shifting network to the collector electrode of said second transistor for application of a portion of said given phase shifted signal thereto, to cause said phase shifted signal as applied to said collector electrode to vectorially add with respect to that signal present due to said signal applied to said base electrode, for providing a changed phase shifted signal at said collector electrode of said second transistor. g. means coupled to the collector electrode of said second transistor for determining the magnitude of said signal to be vectorially added due to said signal applied to said base electrode, for providing said changed phase shifted signal at said collector electrode of said second transistor of changed phase determined in accordance with the magnitude of said signal.

Claim 20

Apparatus for varying the phase of a signal, comprising, a. first and second active devices each having input, output and common terminals, said common terminals connected together and returned to a point of reference potential, b. means coupled to at least one of said input terminals for application of said signal thereto, to provide at said output electrodes, replicas of said signal of a different phase with respect to tone another, c. a phase shift network coupled to said output terminal of said second device for providing at an output thereof said signal of a predetermined phase, d. means including a resistor coupling said output of said shift network to said output terminal of said first active device, e. variable impedance means coupled to said output terminal of said first active device for determining the amount of current that can flow through said resistor due to said signal applied to said input terminal, wherein said signal and said phase shifter signal appears across said resistor, f. means coupled to said resistor responsive to said signal and said phase shifted signal to provide another signal having a phase determined by the vector addition of such signals and therefore by the setting of said variable impedance means.

Claim 21

Apparatus for varying the phase of a signal, comprising, a. first and second active devices each having input, output and common terminals, said common terminals connected together and returned to a point of reference potential, b. means coupled to at least one of said input terminals for application of said signal thereto, to provide at said output electrodes, replicas of said signal of a different phase with respect to tone another, c. a phase shift network coupled to said output terminal of said second device for providing at an output thereof said signal of a predetermined phase, d. means including a resistor coupling said output of said shift network to said output terminal of said first active device, e. variable impedance means coupled to said output terminal of said first active device for determining the amount of current that can flow through said resistor due to said signal applied to said input terminal, wherein said signal and said phase shifter signal appears across said resistor, f. means coupled to said resistor responsive to said signal and said phase shifted signal to provide another signal having a phase determined by the vector addition of such signals and therefore by the setting of said variable impedance means.

Claim 22

The apparatus according to claim 14 wherein, said means including a resistor comprises, a. a power amplifier having an input, output and common terminal said input terminal being coupled to said phase shift network, said output terminal coupling said resistor to said output terminal of said first active device, said common terminal adapted for receiving a source of operating potential.

Claim 23

The apparatus according to claim 14 wherein, said variable impedance means comprises, a. a unidirectional current conducting device having first and second electrodes and poled for easy current conduction between said first and second electrode, having said second electrode coupled to said output terminal of said first active device and b. a variable resistor coupled between said first terminal of said unidirectional device and a point of operating potential.