US 4,736,165 AGranted

Distortion generating circuit

AssigneeHughes Aircraft Company

InventorsJames Chao, Thomas M. Straus

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Abstract

Microwave circuitry is disclosed for a distortion generating circuit. Input and output baluns are disposed on the tap surface of a substrate while secondary and primary conductors are respectively juxtaposed under these baluns. Four diodes connected in a star configuration are coupled between the primary and secondary conductors. The carrier signal may be fed into the input balun which is coupled to the secondary conductors and across the diode star configuration, generating intermodulation signals while suppressing the carrier signals. The intermodulation signal is coupled from the primary conductors to the output balun where it may be fed to a microwave amplifier to cancel intermodulation by-products thereof. A DC signal may be impressed across the diode star configuration to adjust the amplitude of the intermodulation signal generated by the diodes.

Claims9

Dependent claims

A distortion generating circuit for generating third order intermodulation signals based on an RF microwave carrier signal which comprises:

a dielectric substrate having first and second surfaces;
an input balun located on said first surface of said dielectric substrate;
an output balun located on said first surface of said dielectric substrate;
four diodes located on said second surface of said substrate, each of said diodes having one end connected to a common point in a star configuration;
four secondary conductors, each about one quarter wavelength long based on the frequency of said RF carrier signal, juxtaposed under said input balun on said second surface of said substrate, respective ones of said four secondary conductors being connected to respective non-common ends of said four diodes for coupling the RF microwave carrier signal from said input balun to respectives ones of said four diodes such that said RF carrier signal is impressed across said four diodes to generate third order intermodulation signals;
four primary conductors, each about one quarter wavelength long based on the frequency of said RF carrier signal, located on said second surface and juxtaposed under said output balun, respective ones of said primary conductors being coupled to respective non-common ends of said four diodes such that the third order intermodulation signals generated by said four diodes are coupled to said output balun;
and
means for applying a DC voltage bias to the common point of said diode star configuration to control the amplitude of said third order intermodulation signals.

5 more elements

A distortion generating circuit for generating third order intermodulation signals based on a microwave RF carrier signal, comprising:

a dielectric substrate having first and second surfaces;
input balun means located on the first surface of said substrate for converting an unbalanced microwave signal into two balanced microwave signals;
four diodes located on the second surface of said substrate and connected to each other at a common point, two of said diodes being connected cathode-to-cathode and the other two of said diodes being connected anode-to-anode;
secondary conductor means located on the second surface of said substrate and connected to the non-common terminals of said four diodes, said secondary conductor means interacting with said input balun means for coupling microwave signals across said four diodes to generate third order intermodulation signals;
output balun means located on the first surface of said substrate for converting two balanced microwave signals into an unbalanced signal;
primary conductor means located on the second surface of said substrate and connected to the non-common terminals of said four diodes, said primary conductor means interacting with said output balun means for coupling third order intermodulation signals generated by said four diodes to said output balun means;
and
means for applying a DC voltage to said common point of said four diodes to vary the amplitude of said third order intermodulation signals.

5 more elements

A distortion generating circuit comprising:

a dielectric substrate having first and second surfaces;
an input balun located on the first surface of said substrate and having first and second balanced conductors;
first, second, third and fourth secondary conductors each about one quarter wavelength long based on an operating frequency of said circuit, located on the second surface of said substrate, said first and second secondary conductors being juxtaposed under said first balanced conductor and said third and fourth secondary conductors being juxtaposed under said second balanced conductor;
first, second, third and fourth primary conductors, each about one quarter wavelength long based on said operating frequency, located on the second surface of said substrate;
first, second, third and fourth diodes located on the second surface of said substrate, each of said diodes having one end connected to a common point, two of said diodes being coupled anode-to-anode and the other two of said diodes being coupled cathode-to-cathode, respective ones of the non-common ends of said first, second, third and fourth diodes being coupled to respective ones of said first, second, third and fourth secondary conductors and to respective ones of said first, second, third and fourth primary conductors;
an output balun located on the first surface of said substrate and having first and second output balanced conductors, said first output balanced conductor being juxtaposed over said first and second primary conductors and said second balanced output conductor being juxtaposed over said third and fourth primary conductors;
and
means for applying a DC voltage to said common point for biasing said diodes.

5 more elements

Dependencies are inferred from the claim text.