High-frequency Circuit

• US 6,563,366 B1
• Filed: 10/28/1998
• Issued: 05/13/2003
• Est. Priority Date: 10/30/1997
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kohama, Kazumasa
• Primary Examiner(s): Le, Dinh T.
• Application Number:
  US09/179,855
• Time in Patent Office: 1,658 Days
• Field of Search: 327/427, 327/442, 327/567, 327/564, 327/566, 327/379, 327/382, 257/229, 257/275
• US Class Current: 327/382
• CPC Class Codes: H03K 17/6871 the output circuit comprising more than one controlled field-effect transistor

Abstract

A high-frequency circuit, wherein there is provided a switching transistor connected between an input terminal and an output terminal, with a gate electrode connected to a control terminal via a resistance element, and with an effective gate portion of the gate electrode divided into a plurality of sections, and arrangement is made of additional capacitance elements added in parallel to a capacitance between a gate and a source or drain of the switching transistor at positions in proximity to one ends of at least two effective gate sections of the plurality of effective gate sections. Preferably, there is provided a short-circuiting transistor similarly having an additional capacitance element between the output terminal Tout and a reference voltage supply line.

Claims

1. A high-frequency circuit, comprising:

a switching transistor including a source with a source electrode formed on a source region, a drain with a drain electrode formed on a drain region, and a gate with a gate electrode connected to an effective gate portion divided into a plurality of sections, said switching transistor being configured such that;

(1) one of said source electrode and said drain electrode is connected to an input terminal,

(2) the other of said source electrode and said drain electrode is connected to an output terminal, and

(3) said effective gate portion is connected through a resistance element to a control terminal; and

a first additional capacitance element located proximate ends of at least two of the plurality of gate sections and electrically connected between said gate electrode and either of said source electrode or said drain electrode,

wherein said first additional capacitance element is formed by physically overlapping said gate electrode and either of said source electrode or said drain electrode.

2. A high-frequency circuit according to claim 1, further comprising:

a short-circuiting transistor including a source, a drain, and a gate, said short-circuiting transistor being connected between said output terminal and a reference voltage supply line and being held in a non-conductive state when said switching transistor is in a conductive state and which shifts to a conductive state when said switching transistor is in a non-conductive state.

3. A high-frequency circuit according to claim 2, wherein:

said short-circuiting transistor includes a gate having an effective gate portion divided into a plurality of sections, and

said circuit further comprises a second additional capacitance element located proximate ends of at least two of the plurality of said short-circuiting transistor gate sections, said second additional capacitance element being connected in parallel to a capacitance element between said gate and a source or a drain of said short-circuiting transistor.

4. A high-frequency circuit according to claim 1, wherein said switching transistor comprises a plurality of series-connected switching unit transistors having commonly connected gates, and

wherein at least one of the plurality of series-connected switching unit transistors includes said first additional capacitance element.

5. A high-frequency circuit according to claim 2, wherein said short-circuiting transistor circuit comprises a plurality of series-connected short-circuiting unit transistors having commonly connected gates.

6. A high-frequency circuit according to claim 4, further comprising:

a plurality of first additional capacitance elements,

wherein said first additional capacitance elements are connected between said gates, and either said sources or said drains of switching unit transistors positioned at two ends of a line of said series-connected unit transistors.

7. A high-frequency circuit according to claim 5, wherein at least one of said plurality of short-circuiting unit transistors includes a second an additional capacitance element.

8. A high-frequency circuit according to claim 7, further comprising:

a plurality of second additional capacitance elements,

wherein said second additional capacitance elements are connected between said gates, and said sources or said drains of short-circuiting unit transistors positioned at two ends of a line of said series-connected unit transistors.

9. A high-frequency circuit according to claim 1, wherein said first additional capacitance element is formed by interposing an insulating film between said gate and either of said source or said drain.

10. A high-frequency circuit according to claim 3, wherein said second additional capacitance element is formed by interposing an insulating film between two metal layers.

11. A high-frequency circuit according to claim 2, wherein said switching transistor and said short-circuiting transistor are formed on a single semiconductor substrate.

12. A high-frequency circuit according to claim 11, wherein said semiconductor substrate comprises gallium arsenide.

13. A high-frequency circuit according to claim 1, wherein said switching transistor is a junction-type field effect transistor.

14. A high-frequency circuit according to claim 2, wherein said short-circuiting transistor is a junction-type field effect transistor.

15. A high-frequency circuit according to claim 1, wherein said gate electrode is conductive.

16. A high-frequency circuit according to claim 1, wherein said first additional capacitance element provides a means for reducing signal distortion.

17. A high-frequency circuit according to claim 1, wherein said gate electrode is wider than said effective gate portion.