Circuit for compensating for nonlinear characteristics in high-frequency amplifiers

• US 4,068,186 A
• Filed: 06/17/1976
• Issued: 01/10/1978
• Est. Priority Date: 06/24/1975
• Status: Expired due to Term

• Current Assignee: Kokusai Densin Denwa Kabushiki Kaisha
• Original Assignee: Kokusai Densin Denwa Kabushiki Kaisha
• Inventors: Yamaguchi, Masahisa, Sato, Gunkichi
• Primary Examiner(s): Mullins, James B.
• Application Number:
  US05/697,118
• Time in Patent Office: 572 Days
• Field of Search: 330/43, 330/124 R, 330/149, 330/151, 328/163, 325/46, 332/18, 332/37 R, 333/28 R
• US Class Current: 330/149
• CPC Class Codes: H03F 1/3252 using multiple parallel paths between input and output H03F1/3258, H03F1/3282, H03F1/3294 take precedence

Abstract

A circuit for compensating for the nonlinearity in a high-frequency amplifier, in which a pair of a first transmission line and a second transmission line respectively have a delay line and a nonlinear distortion generating high-frequency amplifier. An input signal is divided into two signal parts, which are respectively applied to the first transmission line and the second transmission line. The vector sum of respective outputs of the first transmission line and the second transmission line is obtained to provide a nonlinear characteristic for compensating for the amplitude and phase nonlinear characteristics in the high-frequency amplifier connected in cascade to this circuit.

Claims

1. A circuit, compensating for nonlinearity in a high-frequency amplifier, comprising:

input terminal means for receiving an input signal;

dividing coupler means connected to said input terminal means for dividing the input signal into two signal parts;

a first transmission line comprising a delay line and a phase-frequency characteristic corrector for developing nonlinear phase-frequency characteristics to compensate for a nonlinear characteristic of a high-frequency amplifier requiring compensation, connected to said dividing coupler means for compensation;

one of said two signal parts;

a second transmission line comprising a nonlinear distortion generating high-frequency amplifier for receiving the other of said two signal parts and for developing nonlinear amplitude-frequency characteristics to compensate for the nonlinear characteristic of the high-frequency amplifier requiring compensation;

combining coupler means connected to said first transmission line and said second transmission line for obtaining the vector sum of respective outputs of said first transmission line and said second transmission line; and

output terminal means connected to said combining coupler means for sending out said vector sum to the highfrequency amplifier connected in cascade to said output terminal means for compensating for the amplitude and phase nonlinear characteristics in the high-frequency amplifier requiring compensation.

2. A circuit for compensating for nonlinearity in a high-frequency amplifier comprising:

input terminal means for receiving an input signal;

dividing coupler means connected to said input terminal means for dividing the input signal into two signal parts;

a first transmission line comprising a delay line connected to said dividing coupler means for receiving one of said two signal parts, and comprising a phase-frequency characteristics corrector, which comprises a circulator inserted in the main path thereof and a resonance circuit coupled to said circulator, for developing nonlinear phase-frequency characteristics to compensate for a nonlinear characteristic of a high-frequency amplifier requiring compensation;

a second transmission line comprising a nonlinear distortion generating high-frequency amplifier for receiving the other of said two signal parts and for developing nonlinear amplitude-frequency characteristics to compensate for the nonlinear characteristic of the high-frequency amplifier requiring compensation;

combining coupler means connected to said first transmission line and said second transmission line for obtaining the vector sum of respective outputs of said first transmission line and said second transmission line; and

output terminal means connected to said combining coupler means for sending out said vector sum to the high-frequency amplifier connected in cascade to said output terminal means for compensating for the amplitude and phase nonlinear characteristics in the high-frequency amplifier requiring compensation.

3. A circuit for compensating for nonlinearity in a high-frequency amplifier comprising:

input terminal means for receiving an input signal;

dividing coupler means connected to said input terminal means for dividing the input signal into two signal parts;

a first transmission line comprising a delay line connected to said dividing coupler means for receiving one of said two signal parts;

a second transmission line comprising a first amplitude-frequency characteristic corrector, a nonlinear distortion generating high-frequency amplifier and a second amplitude-frequency characteristic corrector connected in cascade in the named order for receiving the other of said two signal parts and for developing nonlinear amplitude-frequency characteristics to compensate for a nonlinear characteristic of a high-frequency amplifier requiring compensation;

combining coupler means connected to said first transmission line and said second transmission line for obtaining the vector sum of respective outputs of said first transmission line and said second transmission line; and

output terminal means connected to said combining coupler means for sending out said vector sum to the high frequency amplifier connected in cascade to said output terminal means for compensating for the amplitude and phase nonlinear characteristics in the high-frequency amplifier requiring compensation.

4. A circuit for compensating for nonlinearity in a high-frequency amplifier comprising:

input terminal means for receiving an input signal;

dividing coupler means connected to said input terminal means for dividing the input signal into two signal parts;

a first transmission line comprising a delay line connected to said dividing coupler means for receiving one of said two signal parts;

a second transmission line comprising a nonlinear distortion generating high-frequency amplifier and a first amplitude-frequency characteristic corrector connected before said nonlinear distortion generating high-frequency amplifier for receiving the other of said two signal parts, said first amplitude-frequency characteristic corrector comprising a dividing coupler for dividing its input signal into two divided signal parts, amplitude control means receptive to one of said two divided signal parts and comprising two control transmission lines having different electrical lengths, a division signal path receptive of the other of said two divided signal parts and having an electrical length substantially equal to that of said amplitude control means, and a combining coupler connected to said amplitude control means and said division signal path for combining respective outputs of said amplitude control means and said division signal path for developing nonlinear amplitude-frequency characteristics to compensate for a nonlinear characteristic of a high-frequency amplifier requiring compensation;

combining coupler means connected to said first transmission line and said second transmission line for obtaining the vector sum of respective outputs of said first transmission line and said second transmission line; and

output terminal means connected to said combining coupler means for sending out said vector sum to the high frequency amplifier connected in cascade to said output terminal means for compensating for the amplitude and phase nonlinear characteristics in the high-frequency amplifier requiring compensation.

5. A circuit for compensating for nonlinearity in a high-frequency amplifier comprising:

input terminal means for receiving an input signal;

dividing coupler means connected to said input terminal means for dividing the input signal into two signal parts;

a first transmission line comprising a delay line connected to said dividing coupler means for receiving one of said two signal parts;

a second transmission line comprising a nonlinear distortion generating high-frequency amplifier for receiving the other of said two signal parts;

combining coupler means connected to said first transmission line and said second transmission line for obtaining the vector sum of respective outputs of said first transmission line and said second transmission line;

an amplitude-frequency characteristic corrector connected to the output of said combining coupler means and receptive of said vector sum for developing nonlinear amplitude frequency characteristics to compensate for a nonlinear characteristic of a high-frequency amplifier requiring compensation; and

output terminal means connected to said amplitude-frequency characteristic corrector for sending out the output of said amplitude-frequency characteristic corrector to the high frequency amplifier connected in cascade to said output terminal means for compensating for the amplitude and phase nonlinear characteristics in the high-frequency amplifier requiring compensation.

6. A circuit for compensating for nonlinearity in a high-frequency amplifier comprising:

input terminal means for receiving an input signal;

a first amplitude-frequency characteristic corrector connected to said input terminal means;

dividing coupler means connected to said first amplitude-frequency characteristic corrector for dividing the output of said first amplitude-frequency characteristic corrector into two signal parts;

a first transmission line comprising a delay line connected to said dividing coupler means for receiving one of said two signal parts;

a second transmission line comprising a nonlinear distortion generating high-frequency amplifier for receiving the other of said two signal parts;

combining coupler means connected to said first transmission line and said second transmission line for obtaining the vector sum of respective outputs of said first transmission line and said second transmission line;

a second amplitude-frequency characteristic corrector connected to the output of said combining coupler means and receptive of said vector sum, said second amplitude-frequency characteristic corrector comprising a dividing coupler for dividing its input signal in to two divided signal parts, amplitude control means receptive of one of said two divided signal parts and comprising two control transmission lines having different electrical lengths, a division signal path receptive of the other of said two divided signal parts and having an electrical length substantially equal to that of said amplitude control means, and a combining coupler connected to said amplitude control means and said division signal path for combining respective outputs of said amplitude control means and said division signal path for developing nonlinear amplitude-frequency characteristics to compensate for a nonlinear characteristic of a high-frequency amplifier requiring compensation; and

output terminal means connected to said amplitude-frequency characteristics corrector for sending out the output of said second amplitude-frequency characteristic corrector to the high frequency amplifier connected in cascade to said output terminal means for compensating for the amplitude and phase nonlinear characteristics in the high-frequency amplifier requiring compensation.

7. A circuit for compensating for nonlinearity in a high-frequency amplifier comprising:

input terminal means for receiving an input signal;

divising coupler means connected to said input terminal means for dividing the input signal into two signal parts;

a first transmission line comprising a delay line connected to said dividing coupler means for receiving one of said two signal parts and comprising a phase-frequency characteristic corrector, which comprises a directional coupler inserted in the main path thereof and a resonance circuit coupled to said directional for developing nonlinear phase-frequency characteristics to compensate for a nonlinear characteristic of a high-frequency amplifier requiring compensation;

a second transmission line comprising a nonlinear distortion generating high-frequency amplifier for receiving the other of said two signal parts;

combining coupler means connected to said first transmission line and said second transmission line for obtaining the vector sum of respective outputs of said first transmission line and said second transmission and for developing nonlinear amplitude-frequency characteristics to compensate for the nonlinear characteristic of a high-frequency amplifier requiring compensation; and

output terminal means connected to said combining coupler means for sending out said vector sums to the high-frequency amplifier connected in cascade to said output terminal means for compensating for the amplitude and phase nonlinear characteristics in the high-frequency amplifier requiring compensation.

8. A circuit according to claim 7, further comprising a amplitude-frequency characteristic corrector inserted between said combining coupler and said output terminal means.

9. A circuit for compensating for nonlinearity in a high-frequency amplifier comprising:

input terminal means for receiving an input signal;

dividing coupler means connected to said input terminal means for dividing the input signal into two signal parts;

a first transmission line comprising a delay line connected to said dividing coupler means for receiving one of said two signal parts and a phase-frequency characteristic corrector for generating a nonlinear phase-frequency characteristics to compensate for a nonlinear characteristic of a high-frequency amplifier requiring compensation;

a second transmission line comprising a first amplitude-frequency characteristic corrector, a nonlinear distortion generating high-frequency amplifier and a second amplitude-frequency characteristic corrector connected in cascade in the named order for receiving the other of said two signal parts and for developing nonlinear amplitude-frequency characteristics to compensate for the nonlinear characteristic of the high frequency amplifier requiring coompensation;

combining coupler means connected to said first transmission line and said second transmission line for obtaining the vector sum of respective outputs of said first transmission line and said second transmission line; and

output terminal means connected to said combining coupler means for sending out said vector sum to the high frequency amplifier connected in cascade to said output terminal means for compensating for the amplitude and phase nonlinear characteristics in the high-frequency amplifier requiring compensation.

10. A circuit according to claim 9, in which said second amplitude-frequency characteristic corrector comprises a dividing coupler for dividing its input signal into two divided signal parts, amplitude control means receptive of one of said two divided signal parts and comprising two control transmission lines having different electrical lengths, a division signal path receptive of the other of said two divided signal parts and having an electrical length substantially equal to that of said amplitude control means, and a combining coupler connected to said amplitude control means and said division signal path for combining respective outputs of said amplitude control means and said division signal path.

11. A circuit according to claim 9, in which said first amplitude-frequency characteristic corrector comprises a divising coupler for dividing its input signal into two divided signal parts, amplitude control means receptive of one of said two divided signal parts and comprising two control transmission lines having different electrical lengths, a division signal path receptive of the other of said two divided signal parts and having an electrical length substantially equal to that of said amplitude control means, and a combining coupler connected to said amplitude control means and said division signal path for combining respective outputs of said amplitude control means and said division signal path.