In-line predistorter for linearization of electronic and optical signals

An in-line predistorter circuit for generating predistortion that can be used to substantially cancel or reduce the distortion from a nonlinear device, the circuit comprising:

• an RF signal path carrying an RF signal input to the nonlinear device, and a plurality of in-line distortion producing circuit elements placed in sequence along the RF signal path,
• wherein real and imaginary distortion, sufficient to substantially cancel or reduce the distortion from a nonlinear device, is synthesized by additively combining the distortion contributions from the combination of in-line distortion producing circuit elements, and
• wherein at least one of the in-line circuit elements comprises a Schottky diode connected in parallel with a resistor across the RF signal path, with a time delay in series with the resistor, wherein the circuit element produces both real and imaginary distortion.

An in-line predistorter circuit for generating predistortion that can be used to substantially cancel or reduce the distortion from a nonlinear device, the circuit comprising:

• an RF signal path carrying an RF signal input to the nonlinear device, and a Plurality of in-line distortion producing circuit elements placed in sequence along the RF signal path,
• wherein real and imaginary distortion, sufficient to substantially cancel or reduce the distortion from a nonlinear device, is synthesized by additively combining the distortion contributions from the combination of in-line distortion producing circuit elements, and
• wherein at least one of the in-line circuit elements comprises a varactor connected between the main signal path and ground, wherein the circuit element produces primarily imaginary second order distortion.

An in-line predistorter circuit for generating predistortion that can be used to substantially cancel or reduce the distortion from a nonlinear device, the circuit comprising:

• an RF signal path carrying an RF signal input to the nonlinear device, and a plurality of in-line distortion producing circuit elements placed in sequence along the RF signal path,
• wherein real and imaginary distortion, sufficient to substantially cancel or reduce the distortion from a nonlinear device, is synthesized by additively combining the distortion contributions from the combination of in-line distortion producing circuit elements, and
• wherein at least one of the in-line circuit elements comprises a resistor and antiparallel diodes connected in parallel in the RF signal path with a time delay connected in series with the resistor, wherein the circuit produces both real and imaginary components of third order distortion.

An in-line predistorter circuit for generating predistortion that can be used to substantially cancel or reduce the distortion from a nonlinear device, the circuit comprising:

• an RF signal path carrying an RF signal input to the nonlinear device, and a plurality of in-line distortion producing circuit elements placed in sequence along the RF signal path,
• wherein real and imaginary distortion, sufficient to substantially cancel or reduce the distortion from a nonlinear device, is synthesized by additively combining the distortion contributions from the combination of in-line distortion producing circuit elements, and
• wherein at least one of the in-line circuit elements comprises a pair of oppositely directed varactor diodes connected between the RF signal path and ground, wherein the circuit produces imaginary third order distortion.

An in-line predistorter circuit for generating predistortion that can be used to substantially cancel or reduce the distortion from a nonlinear device, the circuit comprising:

• an RF signal path carrying an RF signal input to the nonlinear device, and a plurality of in-line distortion producing circuit elements placed in sequence along the RF signal path,
• wherein real and imaginary distortion, sufficient to substantially cancel or reduce the distortion from a nonlinear device, is synthesized by additively combining the distortion contributions from the combination of in-line distortion producing circuit elements, and
• wherein at least one of the in-line circuit elements comprises a resistor connected to the main RF signal path and two oppositely directed varactor diodes connected to ground, wherein the circuit produces third order distortion that is out of phase with the signal on the main signal path.

An in-line predistorter circuit for generating predistortion that can be used to substantially cancel or reduce the distortion from a nonlinear device, the circuit comprising:

• an RF signal path carrying an RF signal input to the nonlinear device, and a plurality of in-line distortion producing circuit elements placed in sequence along the RF signal path,
• wherein real and imaginary distortion, sufficient to substantially cancel or reduce the distortion from a nonlinear device, is synthesized by additively combining the distortion contributions from the combination of in-line distortion producing circuit elements, and
• wherein at least one of the in-line circuit elements comprises a resistor connected in series with the varactor 252 between the RF signal path and ground, wherein the circuit element produces distortion that includes both real and imaginary parts.