Doherty amplifying apparatus using a harmonic control circuit

• US 20080191801A1
• Filed: 02/11/2008
• Published: 08/14/2008
• Est. Priority Date: 02/14/2007
• Status: Active Grant

• Current Assignee: Postech Academy-Industry Foundation
• Original Assignee: Postech Academy-Industry Foundation
• Inventors: Kim, Bumman, Kim, Jangheon, Woo, Young yun, Moon, Junghwan
• Granted Patent: US 7,663,435 B2
• Time in Patent Office: Days
• US Class Current: 330/124.00R
• CPC Class Codes: H03F 1/0288 using a main and one or several auxiliary peaking amplifiers whereby the load is connected to the main amplifier using an impedance inverter, e.g. Doherty amplifiers
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 2200/222 A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/543 A transmission line being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 3/217 Class D power amplifiers; Switching amplifiers
• CPC Class Codes: H03F 3/604 using FET's

Abstract

A Doherty power amplifying apparatus includes a harmonic-controlled Doherty amplifier; and an input matching unit and an output matching unit for input matching and output matching the harmonic-controlled Doherty amplifier, respectively. The harmonic-controlled Doherty amplifier includes a carrier amplifier; a peaking amplifier arranged in parallel to the carrier amplifier; and a harmonic control circuit, arranged in front of the output matching unit, for controlling a harmonic component of an output of the Doherty amplifier to enable the Doherty amplifier to perform a switching or saturation operation.

Claims

1. A Doherty power amplifying apparatus, comprising:

a harmonic-controlled Doherty amplifier; and

an input matching unit and an output matching unit for input matching and output matching the harmonic-controlled Doherty amplifier, respectively,

wherein the harmonic-controlled Doherty amplifier includes;

a carrier amplifier;

a peaking amplifier arranged in parallel to the carrier amplifier; and

a harmonic control circuit, arranged in front of the output matching unit, for controlling a harmonic component of an output of the Doherty amplifier to enable the Doherty amplifier to perform a switching or saturation operation.

2. The Doherty power amplifying apparatus of claim 1, further comprising:

an offset line, connected to an output end of the Doherty amplifier, for controlling an output of a load impedance of the Doherty amplifier when the peaking amplifier is not operating.

3. The Doherty power amplifying apparatus of claim 1, further comprising:

a quarter-wave transmission line serving as an impedance inverter for performing a ¼

wavelength conversion to enable a Doherty power amplification.

4. The Doherty power amplifying apparatus of claim 1, further comprising:

a quarter-wave transmission line for performing a ¼

wavelength conversion to set a load impedance of the Doherty power amplifying apparatus.

5. The Doherty power amplifying apparatus of claim 1, further comprising:

a transmission line shorter or longer than a ¼

wavelength; and

a passive element,

wherein the transmission line and the passive element are disposed in a manner to enable a Doherty amplification.

6. The Doherty power amplifying apparatus of claim 1, further comprising:

an impedance inverter for enabling a Doherty power amplification.

7. The Doherty power amplifying apparatus of claim 1, wherein the peaking amplifier is off and the carrier amplifier is on in a lower power range, and the peaking amplifier and the carrier amplifier are on in a higher power range.

10. The Doherty power amplifying apparatus of claim 1, wherein the harmonic control circuit includes a microstrip line or a passive element for controlling a second or higher harmonic component.

11. The Doherty power amplifying apparatus of claim 1, wherein the Doherty power amplifier is of the type selected from the group consisting of class D, class E, class F, class G, class H, class I, class J, class S, class E/F series (e.g., class E/F₃, class E/F_2,5, class E/F_odd, class E/F_3,odd), class J/E, inverse class D and inverse class F.

12. The Doherty power amplifying apparatus of claim 1, wherein the carrier amplifier and the peaking amplifiers are arranged such that nonlinear characteristics therebetween are canceled by the switching or the saturation operation.

8. A Doherty power amplifier, comprising:

a carrier amplifier and a plurality of peaking amplifiers, each of the carrier amplifier and the peaking amplifiers includes an input matching unit and an output matching unit;

a N-way power divider for applying a same input power to the carrier amplifier and the peaking amplifiers;

an offset line, connected to each of the output matching units of the carrier amplifier and the peaking amplifiers, for controlling a load impedance output when the peaking amplifiers are not operating;

a first quarter-wave transmission line serving as an impedance inverter for converting an impedance output provided by the offset line into a ¼

wavelength to enable a Doherty amplification;

a second quarter-wave transmission line for converting an impedance output provided by the offset line into a ¼

wavelength to set a load impedance of the Doherty amplifier; and

a harmonic control circuit for controlling a harmonic component in an output of the carrier amplifier and the peaking amplifiers to enable the Doherty amplifier to perform a switching or saturation operation.

13. The Doherty power amplifier of claim 8, wherein the harmonic control circuit is arranged in front of each of the output matching units of the carrier amplifier and the peaking amplifiers, thereby enabling each of the carrier amplifier and the peaking amplifiers to perform a switching or saturation operation.

9. A Doherty power amplifier, comprising:

a carrier amplifier and a plurality of peaking amplifiers, each of the carrier amplifier and the peaking amplifiers includes an input matching unit and an output matching unit;

a N-stage power divider for applying a same input power to the carrier amplifier and the peaking amplifiers;

an offset line, connected to each of the output matching units of the carrier amplifier and the peaking amplifiers, for controlling a load impedance output when the peaking amplifiers are not operating;

a first quarter-wave transmission line serving as an impedance inverter for converting an impedance output provided by the offset line into a ¼

wavelength to enable a Doherty amplification;

a second quarter-wave transmission line for converting an impedance output provided by the offset line into a ¼

wavelength to set a load impedance of the Doherty amplifier; and

a harmonic control circuit for controlling a harmonic component in an output of the carrier amplifier and the peaking amplifiers to enable the Doherty amplifier to perform a switching or saturation operation.