Electrically controlled attenuator

Claim 2

An attenuator comprising input circuit means, output circuit means, inductive coupling means for coupling an AC signal from said input means to said output means, at least two series connected signal cancellation means coupled in series with said coupling means for producing two electrical representations of the signals in phase opposition and so as to produce cancellation of the signal, and DC forward biased diode-pair variable impedance means coupled to each other in series configuration relative to the DC signal and in parallel complementary configuration relative to the AC signal, said diode-pair variable impedance means coupled to said cancellation means at said cancellation means series junction point for varying the degree of cancellation in said cancellation means.

Claim 3

An attenuator as in claim wherein said variable impedance means includes a variable impedance device connected to at least one of said inductive means for varying the impedance in series with said inductive means.

Claim 4

An attenuator as in claim 1 wherein said cancellation means includes a plurality of current-carrying means coupled to each other in signal phase opposition.

Claim 5

An attenuator as in claim 3 wherein conductive means connect one of said current-carrying means to said variable impedance means so that said variable impedance means varies the amplitude of the phase opposing currents in said current-carrying means.

Claim 6

An attenuator as in claim 4 wherein each of said current-carrying means include inductors.

Claim 7

An attenuator as in claim 5 wherein said inductors are coupled to each other in phase opposition.

Claim 8

An attenuator as in claim 6 wherein said inductors are series connected in phase opposition.

Claim 9

An attenuator as in claim 6 wherein said coupling means has an additional inductor coupled to said phase opposed inductors and one of said phase-opposed inductors and said additional inductor are connected to said variable impedance means.

Claim 10

An attenuator as in claim 8 wherein said additional inductor connected to said variable impedance means is connected by said impedance means across said input circuit.

Claim 11

An attenuator as in claim 6 wherein one of said inductors are parallel connected.

Claim 12

An attenuator as in claim 6 wherein one of said inductors is series connected to said variable impedance means.

Claim 13

An attenuator as in claim 11 wherein said coupling means include an additional inductor coupled to said phase-opposed inductors and connected to said output circuit means.

Claim 14

An attenuator as in claim 1 wherein said variable impedance means includes a diode and control means connected to said diode for varying direct current therethrough.

Claim 15

An attenuator comprising: a. input circuit means for impressing an AC signal on said attenuator; b. output circuit means for abstracting an AC signal from said attenuator; c. signal cancellation means coupled to said input and output means further comprising, a transformer having at least three series-connected windings connected sequentially a negative to a negative terminal, and a positive to a positive terminal; d. and DC biased diode-pair variable impedanCe means coupled to each other in series configuration relative to the DC signal and in parallel complementary configuration relative to the AC signal, said diode-pair variable impedance means coupled to said signal cancellation means for varying the degree of cancellation in said cancellation means.

Claim 16

An attenuator comprising: a. input circuit means for impressing an AC signal on said attenuator; b. output circuit means for abstracting an AC signal from said attenuator; c. signal cancellation means coupled to said input and output means further comprising, a transformer having at least three series-connected windings connected sequentially a negative to a negative terminal, and a positive to a positive terminal; d. and DC biased diode-pair variable impedanCe means coupled to each other in series configuration relative to the DC signal and in parallel complementary configuration relative to the AC signal, said diode-pair variable impedance means coupled to said signal cancellation means for varying the degree of cancellation in said cancellation means.

Claim 17

An attenuator as recited in claim 14 including input impedance matching means coupled between said input means and said signal cancellation means and output impedance matching means coupled between said output means and said cancellation means for matching the impedance of said input means and output means to said cancellation means.

Claim 18

An attenuator as recited in claim 15 wherein said input and output matching means comprise a first capacitor coupled in parallel to a series-connected second capacitor and inductor.

Claim 19

An attenuator as recited in claim 14 wherein the combined impedance of said windings corresponds to that of the inductance to one of the windings.

Claim 20

An attenuator as recited in claim 17 wherein said diode means are directly coupled to said primary and secondary windings at their junction.

Claim 21

An attenuator as recited in claim 17 wherein the signal to be controlled is applied to the primary winding, and wherein the impedance of the diode means is varied to vary the inductance of said primary winding thus varying the self-induced voltage of said primary winding, and wherein the induced voltage of said secondary is cancelled by the opposite substantially equal induced voltage of said tertiary winding.

Claim 22

An attenuator as recited in claim 14 wherein said windings are individually wound independently one from the other.

Claim 23

An attenuator as recited in claim 14 wherein said diode pair variable impedance means are coupled cathode to anode.

Claim 24

An attenuator comprising: a. input circuit means for comprising an AC signal on said attenuator; b. output circuit means for abstracting an AC signal from said attenuator; c. inductive coupling means for coupling the signal from said input means to said output means; d. input-impedance-matching means coupled between said input means and said inductive coupling means for matching the impedance of said input means to that of said coupling means, said input-impedance-matching means further comprising a first capacitor in parallel with a first inductor; e. output-impedance-matching means coupled between said output means and said inductive coupling means for matching the impedance of said output means to that of said coupling means, said output-matching means further comprising a second capacitor in parallel with a second inductor; f. at least two parallel connected signal cancellation means coupled in parallel to said inductive coupling means for producing two electrical representations of the signal in phase opposition and so as to produce cancellation of the signal; g. and diode-pair variable impedance means coupled cathode to anode, and further parallel coupled to said parallel connected signal cancellation means for varying the degree of cancellations in said cancellation means.

Claim 25

An attenuator comprising: a. input circuit means for comprising an AC signal on said attenuator; b. output circuit means for abstracting an AC signal from said attenuator; c. inductive coupling means for coupling the signal from said input means to said output means; d. input-impedance-matching means coupled between said input means and said inductive coupling means for matching the impedance of said input means to that of said coupling means, said input-impedance-matching means further comprising a first capacitor in parallel with a first inductor; e. output-impedance-matching means coupled between said output means and said inductive coupling means for matching the impedance of said output means to that of said coupling means, said output-matching means further comprising a second capacitor in parallel with a second inductor; f. at least two parallel connected signal cancellation means coupled in parallel to said inductive coupling means for producing two electrical representations of the signal in phase opposition and so as to produce cancellation of the signal; g. and diode-pair variable impedance means coupled cathode to anode, and further parallel coupled to said parallel connected signal cancellation means for varying the degree of cancellations in said cancellation means.

Claim 26

An attenuator as recited in claim 22 wherein said diode pair variable impedance means comprise a first resistor in parallel with a first diode, a third capacitor in parallel with said first resistor and first diode, and a second diode in parallel with said first diode.