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US 4,314,288 AGranted
Amplitude and phase equalizer
AssigneeAmpex Corporation
InventorMaung Gyi
Life of this patent
Estimating the term…
Abstract
Minimal realization of an optimum amplitude and phase equalizer is disclosed. A first amplifier circuit including first respective passive filter elements provides both high and low frequency amplitude equalization. A second amplifier circuit including second respective passive filter elements provides first, second or higher order phase equalization, respectively, with gain. The equalizer operates between voltage sources and virtual ground to minimize noise picked up from parasitic capacities and external sources.
Claims18
An amplitude and phase equalization circuit, comprising in combination:
- an input terminal for receiving an input signal to be amplitude and phase equalized within a given frequency band;
- a first amplifier means having an inverting input, a non-inverting input coupled to ground, and an output for providing an amplitude equalized output signal;
- a first passive filter means coupled between said input terminal and said inverting input of said first amplifier means to provide an increasing amplitude characteristic with frequency at said output of the first amplifier means within a known high frequency portion of said given frequency band;
- a second passive filter means coupled between said output and inverting input of said first amplifier means to provide a decreasing amplitude characteristic with frequency at said output of the first amplifier means within a known low frequency portion of said given frequency band, said amplitude equalized output signal obtained at said output of the first amplifier means having a non-linear phase characteristic with frequency within said given frequency band;
- a second amplifier means having an inverting and a non-inverting input, respectively, and an output, an input impedance coupled between said output of said first amplifier means and said inverting input of the second amplifier means, a feedback impedance coupled between said output of the second amplifier means and its inverting input;
- and
- a third passive filter means of a selected order coupled between said output of the first amplifier means, said non-inverting input of the second amplifier means and ground, respectively, to provide at said output of the second amplifier means an amplitude and phase equalized output signal having a substantially linearly increased amplitude with respect to said output signal of said first amplifier means and having a substantially linear phase characteristic with frequency within said given frequency band.
4 more elements
An amplitude equalization circuit comprising in combination:
- an input terminal for receiving an input signal to be amplitude equalized within a given frequency band;
- an operational amplifier means having an inverting input, a non-inverting input coupled to ground and an output for providing an amplitude equalized output signal;
- a first passive filter means having an input coupled to said input terminal and having an output coupled to said inverting input of said operational amplifier means, said first passive filter means comprises a first series combination of a capacitor, inductor and resistor, said first series combination being coupled in parallel with a first resistor;
- and
- a second passive filter means coupled between said inverting input and output of said amplifier means, said second passive filter means comprises a second series combination of a resistor and capacitor, said second series combination being coupled in parallel with a second resistor.
2 more elements
A phase equalization circuit comprising in combination:
- an input terminal for receiving an input signal having a non-linear phase characteristic with frequency within a given frequency band;
- an operational amplifier means having an inverting and a non-inverting input, respectively, and an output, an input impedance coupled between said input terminal and said inverting input of said amplifier means, and a feedback impedance coupled between said inverting input and said output of said amplifier means;
- and
- a passive reactive filter means of a selected order coupled between said input terminal, said non-inverting input of said amplifier means and ground, respectively, to provide at said output of said amplifier means a phase equalized output signal having a substantially linearly increased amplitude with respect to said input signal and having a substantially linear phase characteristic with frequency within said given frequency band.
1 more element
A phase equalization circuit comprising in combination:
- an input terminal (90) for receiving an input signal having a non-linear phase characteristic with frequency within a given frequency band;
- an operational amplifier means (92) having an inverting (96) and a non-inverting input (98), respectively, and an output (95), an input impedance (94) coupled between said input terminal (90) and said inverting input (96) of said amplifier means (92), and a feedback impedance (106) coupled between said inverting input (96) and said output (95) of said amplifier means (92);
- and
- a passive reactive filter means (114) comprising a resistor (110) coupled between said input terminal (90) and said non-inverting input (98) of said amplifier means (92) and a capacitor (112) coupled between said non-inverting input (98) and ground, respectively, for providing a first order phase equalization circuit with gain.
1 more element
A phase equalization circuit comprising in combination:
- an input terminal (90) for receiving an input signal having a non-linear phase characteristic with frequency within a given frequency band;
- an operational amplifier means (92) having an inverting (96) and a non-inverting input (98), respectively, and an output (95), an input impedance (94) coupled between said input terminal (90) and said inverting input (96) of said amplifier means (92), and a feedback impedance (106) coupled between said inverting input (96) and said output (95) of said amplifier means (92);
- and
- a passive reactive filter means (120) comprising a series combination of a first resistor (122), an inductor (124) and a capacitor (126), coupled between said input terminal (90) and said non-inverting input (98) of said amplifier means (92), and a second resistor (128) coupled between said non-inverting input (98) and ground, respectively, for providing a second order phase equalization circuit with gain.
1 more element
Dependencies are inferred from the claim text.