US3898591A — Dispersive delay devices

Claim 1

Independent Claim 89 words

A dispersive delay device for time compressing a frequency swept input pulse, including dispersive delay means operative to produce from the input pulse an output signal in the form of a central spike flanked by two side lobes and means for deriving from the input pulse at least one correction pulse which is frequency swept in the opposite direction to the input pulse and for subtracting the, or each, derived correction pulse from a, or a respective, side lobe so as to reduce the amplitude of the side lobe.

Claim 2

Dependent Claim 89 words

A dispersive delay device for time compressing a frequency swept input pulse, including dispersive delay means operative to produce from the input pulse an output signal in the form of a central spike flanked by two side lobes and means for deriving from the input pulse at least one correction pulse which is frequency swept in the opposite direction to the input pulse and for subtracting the, or each, derived correction pulse from a, or a respective, side lobe so as to reduce the amplitude of the side lobe.

Claim 3

Dependent Claim 36 words

A delay device as claimed in claim 1 in which the, or each, correction pulse has a greater amplitude than the side lobes and means, such as a capacitor, are provided for attenuating the correction pulse.

Claim 4

Dependent Claim 24 words

A dispersive delay device as defined in claim 1 wherein the, or each, correction pulse corresponds in time only to a respective side lobe.

Claim 5

Dependent Claim 135 words

A dispersive delay device for time compressing a frequency swept input pulse, including dispersive delay means operative to produce from the input pulse an output signal in the form of a central spike flanked by two side lobes and means for driving from the input pulse at least one correction pulse which is frequency swept in the opposite direction to the input pulse and for subtracting the, or each, derived correction pulse from a, or a respective, side lobe so as to reduce the amplitude of the side lobe, and in which two correction signals are derived from the input signal for reducing the amplitude of both side lobes, each signal being produced by a further dispersive delay means of which the sweep rate is one half of that of the first mentioned delay means.

Claim 6

Dependent Claim 135 words

A dispersive delay device for time compressing a frequency swept input pulse, including dispersive delay means operative to produce from the input pulse an output signal in the form of a central spike flanked by two side lobes and means for driving from the input pulse at least one correction pulse which is frequency swept in the opposite direction to the input pulse and for subtracting the, or each, derived correction pulse from a, or a respective, side lobe so as to reduce the amplitude of the side lobe, and in which two correction signals are derived from the input signal for reducing the amplitude of both side lobes, each signal being produced by a further dispersive delay means of which the sweep rate is one half of that of the first mentioned delay means.

Claim 7

Dependent Claim 39 words

A delay device as claimed in claim 4, in which Both the first mentioned dispersive delay means and the further delay means are formed by a set of transducers on a common piezoelectric substrate, such as a quartz crystal.

Claim 8

Dependent Claim 68 words

A delay device as claimed in claim 5, in which the dispersive delay means are formed by surface wave delay lines each of which includes a sending and a receiving transducer formed on the same surface of a piezoelectric crystal and each comprising a pair of interdigitated comb-like electrodes, the spacing between adjacent fingers of at least one of the transducers being graded to achieve the desired dispersion.

Claim 9

Dependent Claim 40 words

A delay device as claimed in claim 6, in which the first mentioned dispersive delay means and the further delay means have a common sending transducer and the receiving transducers are arranged on the same side of the sending transducer.

Claim 10

Dependent Claim 38 words

A delay device as claimed in claim 7, in which in order to vary the insertion loss of the delay device with frequency, the overlap between adjacent fingers of the electrodes in the common sending transducer is varied.

Claim 11

Dependent Claim 143 words

A dispersive delay device for time compressing a frequency swept input pulse, comprising in combination: dispersive delay means connected to the input pulse and having a center frequency delay nT and a bandwidth fmin to fmax for sweeping from fmin to fmax in a time period T to produce a first output signal in the form of a central spike flanked by two side lobes; at least one further dispersive delay means connected to the input signal and having a center frequency delay (n + or - )T and a bandwidth fmin to fmax for sweeping from fmin to fmax in a time period 2T to produce a second output signal corresponding in time and frequency content to one of said side lobes; and means for subtracting said second output signal from said first output signal substantially to eliminate said one side lobe.

Claim 12

Dependent Claim 143 words

A dispersive delay device for time compressing a frequency swept input pulse, comprising in combination: dispersive delay means connected to the input pulse and having a center frequency delay nT and a bandwidth fmin to fmax for sweeping from fmin to fmax in a time period T to produce a first output signal in the form of a central spike flanked by two side lobes; at least one further dispersive delay means connected to the input signal and having a center frequency delay (n + or - )T and a bandwidth fmin to fmax for sweeping from fmin to fmax in a time period 2T to produce a second output signal corresponding in time and frequency content to one of said side lobes; and means for subtracting said second output signal from said first output signal substantially to eliminate said one side lobe.

Claim 13

Dependent Claim 97 words

A dispersive delay device as defined in claim 9 wherein the center frequency delay of said further dispersive delay means is (n+)T and including a third dispersive delay means connected to said input pulse and having a center frequency delay (n-)T and a bandwidth fmin to fmax for sweeping from fmin to fmax in a time period 2T to produce a third output signal corresponding in time and frequency content to the other of said side lobes, and means for subtracting said third output signal from said first output signal substantially to eliminate said other side lobe.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-08-04	1979-02-03	1979-08-05	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-08-04	1983-02-03	1983-08-05	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-08-04	1987-02-03	1987-08-05	$7700.00	Window Closed / Lapsed

Dispersive delay devices

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