High-frequency amplifier circuit, semiconductor device, and magnetic recording and reproducing device

Patent metadata

Field	Value
Publication number	US-9252716-B2
Application number	US-201414250118-A
Country	US
Kind code	B2
Filing date	Apr 10, 2014
Priority date	Apr 18, 2013
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

A high-frequency amplifier circuit includes a balanced-unbalanced converter converting a single-ended signal into differential signals. The output of a first amplifier amplifying the single-ended signal is connected to the signal terminal on the unbalanced side of the balanced-unbalanced converter. The input of a second amplifier amplifying one of the differential signals is connected to one signal terminal on the balanced side of the balanced-unbalanced converter. The input of a third amplifier amplifying another of the differential signals is connected to another signal terminal on the balanced side of the balanced-unbalanced converter. An impedance element is inserted between an element on the balanced side of the balanced-unbalanced converter and a ground.

First claim

What is claimed is:

1. A high-frequency amplifier circuit comprising:
a balanced-unbalanced converter converting a single-ended signal into differential signals, wherein
an output of a first amplifier amplifying the single-ended signal is connected to a signal terminal on an unbalanced side of the balanced-unbalanced converter,
an input of a second amplifier amplifying one of the differential signals is connected to one signal terminal on a balanced side of the balanced-unbalanced converter,
an input of a third amplifier amplifying another of the differential signals is connected to another signal terminal on the balanced side of the balanced-unbalanced converter, and
an impedance element is inserted between an element on the balanced side of the balanced-unbalanced converter and a ground,
wherein the impedance element includes at least on resistive element; and
wherein the impedance element includes a plurality of resistive elements connected in series and, to a front and a back of at least one of the plurality of resistive elements, a wiring line short-circuiting the at least one resistive element or a wiring line including an opening is connected.

2. The high-frequency amplifier circuit according to claim 1 , wherein the impedance element has an impedance that is equal to approximately a quarter of a combined impedance of the second amplifier and the third amplifier.

3. A semiconductor device comprising the high-frequency amplifier circuit according to claim 1 formed therein.

4. A magnetic recording and reproducing device comprising the high-frequency amplifier circuit according to claim 1 mounted therein.

5. A magnetic recording and reproducing device comprising the semiconductor device according to claim 3 mounted therein.

6. A high-frequency amplifier circuit comprising:
a balanced-unbalanced converter converting a single-ended signal into differential signals, wherein
an output of a first amplifier amplifying the single-ended signal is connected to a signal terminal on an unbalanced side of the balanced-unbalanced converter,
an input of a second amplifier amplifying one of the differential signals is connected to one signal terminal on a balanced side of the balanced-unbalanced converter,
an input of a third amplifier amplifying another of the differential signals is connected to another signal terminal on the balanced side of the balanced-unbalanced converter, and
an impedance element is inserted between an element on the balanced side of the balanced-unbalanced converter and a ground,
wherein the impedance element has an impedance that is equal to approximately a quarter of a combined impedance of the second amplifier and the third amplifier.

7. The high-frequency amplifier circuit according to claim 6 , wherein the impedance element includes at least one resistive element.

8. The high-frequency amplifier circuit according to claim 7 , wherein the impedance element includes a plurality of resistive elements connected in series and, to a front and a back of at least one of the plurality of resistive elements, a wiring line short-circuiting the at least one resistive element or a wiring line including an opening is connected.

9. A semiconductor device comprising the high-frequency amplifier circuit according to claim 6 formed therein.

10. A magnetic recording and reproducing device comprising the high-frequency amplifier circuit according to claim 6 mounted therein.

11. A magnetic recording and reproducing device comprising the semiconductor device according to claim 9 mounted therein.

Assignees

• Tdk Corp

Inventors

• Yoneda Sadaharu
• Ajioka Atsushi
• Shibuya Tomohiko
• Tsumita Atsushi

Classifications

• H03F3/45928

  using IC blocks as the active amplifying circuit · CPC title

• H03F1/083 Primary

  in transistor amplifiers (H03F1/10 - H03F1/22 take precedence) · CPC title

• H03F2200/405

  the output amplifying stage of an amplifier comprising more than three power stages · CPC title

• H03F3/19

  with semiconductor devices only · CPC title

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title