US3906409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable impedance delay line correlator
Assignee: United States Department of the Navy
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Filing: 1974-05-23
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Granted: 1975-09-16
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Expires: 1994-05-23
Abstract
Abstract A variable-impedance delay-line correlator comprising a hybrid coupler, having an input port, a common port and an output port, at the input port of which may be applied an arbitrary input signal X1(t). The correlator includes a variable impedance delay line, whose input is connected to the common port of the hybrid coupler, the delay line also being connectable to an input control signal X2(t) of variable amplitude, the output of the delay line being terminated in its nominal characteristic impedance Z0. The delay line comprises a set of elements having relative values of reactance such that, with an arbitrary input signal X1(t) and with the control voltage X2(t) varying in magnitude and in steps and at uniformly spaced times gamma j which satisfy the sampling theorem for X2(t), the output signal at the output port of the delay line, will be X1(t) (d/dtX2(t), where the symbol indicates the correlation of the input signal X1(t) with the derivative of the control signal X2(t).
Inventors
- 👤 Harper John Whitehouse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:07
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/19; G06G7/195
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
160 words
A variable-impedance delay-line correlator comprising: a hybrid coupler, having an input port, a common port and an output port, at the input port of which may be applied an arbitrary input signal X1(t); a variable impedance delay line, whose input is connected to the common port of the hybrid coupler, the delay line also being connectable to an input control signal X2(t) of variable amplitude, the output of the delay line being terminated in its nominal characteristic impedance Z0; the delay line comprising a set of elements having relative values of reactance such that, with an arbitrary input signal X1(t) and with the control signal X2(t) varying in magnitude and in steps and at uniformly spaced times Yj which satisfy the sampling theorem for X2(t), the output signal at the output port of the delay line will be X1(t) (d/dt) X2(t), where the symbol indicates the correlation of the input signal X1(t) with the derivative of the cOntrol signal X2(t).
Claim 2
Dependent Claim
160 words
A variable-impedance delay-line correlator comprising: a hybrid coupler, having an input port, a common port and an output port, at the input port of which may be applied an arbitrary input signal X1(t); a variable impedance delay line, whose input is connected to the common port of the hybrid coupler, the delay line also being connectable to an input control signal X2(t) of variable amplitude, the output of the delay line being terminated in its nominal characteristic impedance Z0; the delay line comprising a set of elements having relative values of reactance such that, with an arbitrary input signal X1(t) and with the control signal X2(t) varying in magnitude and in steps and at uniformly spaced times Yj which satisfy the sampling theorem for X2(t), the output signal at the output port of the delay line will be X1(t) (d/dt) X2(t), where the symbol indicates the correlation of the input signal X1(t) with the derivative of the cOntrol signal X2(t).
Claim 3
Dependent Claim
41 words
The variable-impedance delay-line correlator of claim 1, including a low pass filter having a response (sin x/x) and a first zero at f (1/ gamma ), capable of reconstructing the output signal X1(t) d/dt X2(t) into its components X1(t) and X2(t).
Claim 4
Dependent Claim
23 words
A variable-impedance delay-line correlator according to claim 1, further comprising: means connected to the variable impedance delay line for generating the control signal.
Claim 5
Dependent Claim
80 words
A variable-impedance delay-line correlator according to claim 3, wherein the variable-impedance delay line comprises a ladder network of variable series inductors and variable parallel capacitors; and means for simultaneously varying the inductance of each inductor and the capacitance of each capacitor corresponding to the variation of the signal X2(t); the inductors and capacitors having relative values of reactance such that, in operation, the current through the inductors and the voltage across the capacitors are both proportional to the signal X2(t).
Claim 6
Dependent Claim
111 words
A variable-impedance delay-line correlator according to claim 1, wherein the hybrid coupler comprises: a set of interdigitated electrodes, disposed upon a substrate, which comprise the input port at which the arbitrary input signal X1(t) may be applied: the variable impedance line comprises: a relatively thin, generally rectangular, conductive plate disposed parallel to the substrate to one side of the interdigitated electrodes; means for separating the conductive plate from the substrate; means for impressing the X2(t) signal broadside to the conductive plate; and a conductive sheet disposed upon the substrate on the opposite side from the separating means; the signal X2(t) being impressed between the signal impressing means and the conductive sheet.
Claim 7
Dependent Claim
41 words
The correlator according to claim 5, wherein the separating means comprises two narrow rails disposed on each side of the conductive plate, the rails comprising an insulating material, for example silicon dioxide; and the signal impressing means comprises a bulk-wave transducer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |