Constant pulse width generator

Claim 2

A pulse generator for providing output pulses of substantially constant width in response to input pulses of variable width and amplitude comprising: a signal input terminal adapted to receive said input pulses; a differential amplifier having two inputs and an output; a first coupling means located between said signal input terminal and a first of said inputs of said differential amplifier; a second coupling means including a series resistor located between said signal input terminal and The second input terminal of said differential amplifier; a constant current source coupled to said second coupling means between said resistor and said second input terminal to provide a constant D.C. current through said series resistor causing an offset voltage of a given potential at said second input terminal of said differential amplifier, with said offset being independent of said input pulse width or amplitude, so that said input pulses as received at said first amplifier input are distorted in a given sense but as received at said second amplifier input are without said distortion; said differential amplifier providing an output pulse of given width when the amplitude level at a selected one of the amplifier inputs exceeds the amplitude level at a non-selected one of said amplifier inputs.

Claim 3

A pulse generator for providing an output pulse signal of substantially constant pulse width in response to an input pulse signal of variable pulse width and amplitude comprising: a signal input terminal adapted to receive said input pulse signal; a differential amplifier having two inputs and an output; a first series resistor coupled by a first coupling means between said signal input terminal and a first of said inputs of said differential amplifier responsive to said input pulse signal to convert said input pulse signal to integrated signals of a given slope; a second resistor and a bypass capacitor coupled across said second resistor to form a resistor-capacitor network; said resistor-capacitor network coupled in series by a second coupling means between said signal input terminal and the second input terminal of said differential amplifier responsive to said input pulse signal to pass said input pulse signal without any substantial integration; a constant current source included in said second coupling means at a point between said second resistor and said second input terminal of said differential amplifier for providing a constant current through said second resistor causing an offset voltage of a given potential at said second input terminal with the offset voltage being independent of the input signal pulse width or amplitude; said differential amplifier providing an output pulse of given width when the amplitude level at a selected one of the amplifier inputs exceeds the amplitude level at a non-selected one of said amplifier inputs.

Claim 4

A pulse generator for providing an output pulse signal of substantially constant pulse width in response to an input pulse signal of variable pulse width and amplitude comprising: a signal input terminal adapted to receive said input pulse signal; a differential amplifier having two inputs and an output; a first series resistor coupled by a first coupling means between said signal input terminal and a first of said inputs of said differential amplifier responsive to said input pulse signal to convert said input pulse signal to integrated signals of a given slope; a second resistor and a bypass capacitor coupled across said second resistor to form a resistor-capacitor network; said resistor-capacitor network coupled in series by a second coupling means between said signal input terminal and the second input terminal of said differential amplifier responsive to said input pulse signal to pass said input pulse signal without any substantial integration; a constant current source included in said second coupling means at a point between said second resistor and said second input terminal of said differential amplifier for providing a constant current through said second resistor causing an offset voltage of a given potential at said second input terminal with the offset voltage being independent of the input signal pulse width or amplitude; said differential amplifier providing an output pulse of given width when the amplitude level at a selected one of the amplifier inputs exceeds the amplitude level at a non-selected one of said amplifier inputs.

Claim 5

The combination claimed in claim 2 wherein said first and second series resistors are of equal value.

Claim 6

In a generator of phase modulated signals of the type including a source of sawtooth waves of substantially constant frequency, a source of modulating signals, at least one wave shape modifying means responsive to the modulating signals and said sawtooth waves and arranged to convert said sawtooth waves to rectangular waves whose width and position are directly proportional to the instantaneous magnitude of said modulating signals and wherein said rectangular waves due to changes in the operating characteristics of said generator are of varying amplitude resulting in unwanted amplitude modulation in the phase modulated signal, the improvement therewith for providing substantially constant pulse width signals of a pulse position directly proportional to the instantaneous magnitude of said modulating signals regardless of the amplitude and pulse width of said rectangular waves comprising, in combination; a differential amplifier having two inputs and an output; a first series resistor coupled by a first coupling means between said wave shape modifying means and a first of said inputs of said differential amplifier responsive to said rectangular waves for coupling integrated waves of a given slope at the first input terminal of said amplifier; a second series resistor and a bypass capacitor coupled across said second resistor forming a resistor-capacitor network, said resistor-capacitor network coupled in series by a second coupling means between said wave sHape modifying means and the second input terminal of said differential amplifier responsive to said rectangular waves for coupling said rectangular waves without substantial integration at the second input terminal of said amplifier; a constant current source included in said second coupling means between said second resistor and said second input terminal of said differential amplifier for providing a constant D.C. current through said second resistor causing an offset voltage of a given potential at said second input terminal with said offset being independent of the pulse width or amplitude of said rectangular waves; said differential amplifier providing an output pulse of given width when the amplitude level at a selected one of the two amplifier inputs exceeds the amplitude level at a non-selected one of said amplifier inputs.

Claim 7

In a generator of phase modulated signals of the type including a source of sawtooth waves of substantially constant frequency, a source of modulating signals, at least one wave shape modifying means responsive to the modulating signals and said sawtooth waves and arranged to convert said sawtooth waves to rectangular waves whose width and position are directly proportional to the instantaneous magnitude of said modulating signals and wherein said rectangular waves due to changes in the operating characteristics of said generator are of varying amplitude resulting in unwanted amplitude modulation in the phase modulated signal, the improvement therewith for providing substantially constant pulse width signals of a pulse position directly proportional to the instantaneous magnitude of said modulating signals regardless of the amplitude and pulse width of said rectangular waves comprising, in combination; a differential amplifier having two inputs and an output; a first series resistor coupled by a first coupling means between said wave shape modifying means and a first of said inputs of said differential amplifier responsive to said rectangular waves for coupling integrated waves of a given slope at the first input terminal of said amplifier; a second series resistor and a bypass capacitor coupled across said second resistor forming a resistor-capacitor network, said resistor-capacitor network coupled in series by a second coupling means between said wave sHape modifying means and the second input terminal of said differential amplifier responsive to said rectangular waves for coupling said rectangular waves without substantial integration at the second input terminal of said amplifier; a constant current source included in said second coupling means between said second resistor and said second input terminal of said differential amplifier for providing a constant D.C. current through said second resistor causing an offset voltage of a given potential at said second input terminal with said offset being independent of the pulse width or amplitude of said rectangular waves; said differential amplifier providing an output pulse of given width when the amplitude level at a selected one of the two amplifier inputs exceeds the amplitude level at a non-selected one of said amplifier inputs.