High-frequency, broadband amplifier circuit

1. A high-frequency, broadband amplifier circuit comprising:

two drive elements configured to perform push-pull operation, thereby to amplify a high-frequency signal and outputting the signal amplified;

a matching circuit including two pattern circuits connected to the outputs of the two drive elements, respectively, the pattern circuits configured to convey, in differential mode, the high-frequency signals supplied from the two drive elements;

a Balun circuit configured to convert the high-frequency signals output from the matching circuit to a single-end mode signal;

a power supply connected one of the pattern circuits; and

a power supply circuit connecting the two pattern circuits and configured to supply at least the output of the power supply to the other pattern circuit;

wherein the power supply includes an inductance component; and

the inductance component has impedance 20 or more times the impedance of the two drive elements and is set to a value equal to or less than 1 ohm at a frequency equal to or lower than the modulation frequency of the high-frequency signal.

2. The high-frequency, broadband amplifier circuit according to claim 1 ,

wherein the impedance of the inductance component is set in accordance with the following formulae:

2π· f RF ·L≧ 20· Z FET

2π· f MOD ·L≦ 1,

where L is the inductance component, f RF is the frequency band of the high-frequency signal, f MOD is the modulation frequency of the high-frequency signal, and Z FET is the impedance of two output FET elements used as the two drive elements.

3. The high-frequency, broadband amplifier circuit according to claim 1 ,

wherein the power supply circuit includes a capacitor component that cancels the impedance of the inductance component.

4. The high-frequency, broadband amplifier circuit according to claim 3 ,

wherein a capacitance element including the capacitor component has such capacitance as to resonate with an inductance element including the inductance component, in the frequency band of the high-frequency signal.

5. A high-frequency, broadband amplifier circuit comprising:

two drive elements configured to perform push-pull operation, thereby to amplify a high-frequency signal and outputting the signal amplified;

a matching circuit including two pattern circuits connected to the outputs of the two drive elements, respectively, the pattern circuits configured to convey, in differential mode, the high-frequency signals supplied from the two drive elements;

a Balun circuit configured to convert the high-frequency signals output from the matching circuit to a single-end mode signal;

a power supply connected one of the pattern circuits; and

a power supply circuit connecting the two pattern circuits and configured to supply at least the output of the power supply to the other pattern circuit;

wherein the power supply circuit includes an inductance component and a capacitor component that cancels the impedance of the inductance component; and

a capacitance C of the capacitor component is set so as to satisfy the following formulae in such a manner that a capacitance element including the capacitor component resonates with an inductance element including the inductance component in the frequency band of the high-frequency signal:

2π· f RF ·L= ½π· f RF ·C

2π· f MOD ·L≦ 1

wherein L is an inductance of the inductance component, f RF is the frequency band of the high-frequency signal, and f MOD is the modulation frequency of the high-frequency signal.

6. The high-frequency, broadband amplifier circuit according to claim 4 ,

wherein a capacitance C of the capacitor component is set so as to satisfy the following formulae:

2π· f RF ·L= ½π· f RF ·C

2π· f MOD ·L≦ 1

wherein L is an inductance of the inductance component, f RF is the frequency band of the high-frequency signal, and f MOD is the modulation frequency of the high-frequency signal.

7. The high-frequency, broadband amplifier circuit according to claim 1 ,

wherein the power supply circuit includes an impedance matching circuit configured to adjust an overall impedance of the power supply circuit.

8. The high-frequency, broadband amplifier circuit according to claim 5 ,

wherein the power supply circuit includes an impedance matching circuit configured to adjust an overall impedance of the power supply circuit.

9. A high-frequency, broadband amplifier circuit comprising:

two drive elements configured to perform push-pull operation, thereby to amplify a high-frequency signal and outputting the signal amplified;

a matching circuit including two pattern circuits connected to the outputs of the two drive elements, respectively, the pattern circuits configured to convey, in differential mode, the high-frequency signals supplied from the two drive elements;

a Balun circuit configured to convert the high-frequency signals output from the matching circuit to a single-end mode signal;

a power supply connected one of the pattern circuits; and

a power supply circuit connecting the two pattern circuits and configured to supply at least the output of the power supply to the other pattern circuit;

wherein the power supply circuit includes an inductance element including an inductance component and an impedance matching circuit which comprises a series circuit composed of an inductance circuit and a capacitance element and connected to a connection node of the matching circuit and the inductance element including the inductance component; and

the inductance circuit is adjustable in pattern length.

10. The high-frequency, broadband amplifier circuit according to claim 1 ,

wherein the power supply circuit includes a coil element or a wire, which has an inductance component.

11. The high-frequency, broadband amplifier circuit according to claim 9 ,

wherein the inductance circuit includes a coil element or a wire, which has an inductance component.