Diode compensation circuit including two series and one parallel resonance points

• US 6,496,083 B1
• Filed: 02/03/1999
• Issued: 12/17/2002
• Est. Priority Date: 06/03/1997
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Takahashi, Hiroshi, Yuda, Naoki, Fujikawa, Makoto, Kushitani, Hiroshi
• Primary Examiner(s): Bettendorf, Justin P.
• Application Number:
  US09/242,139
• Time in Patent Office: 1,413 Days
• Field of Search: 333/103, 333/104, 333/132, 455/78, 455/82, 455/83
• US Class Current: 333/103
• CPC Class Codes: H01P 1/15 by semiconductor devices

Abstract

The present invention aims to realize, in regard to a high frequency switch used for a mobile communication apparatus such as a portable telephone or the like, a dual band switch having simple structure and changeable to ON and OFF states in two bands. For realizing the aim, the present invention provide a dual band switch comprising a series circuit of a PIN diode (101) and its compensation circuit (102), and, the compensation circuit (102) is formed with a circuit having at least two series resonance points and one parallel resonance point. The above structure allows the impedance of the compensation circuit, which is capacitive in low frequency close to a direct current, to be inductive after undergoing the first series resonance point, whereby the parasitic capacity of the diode is canceled in the first band, and also to be inductive again after undergoing the parallel resonance point and the following series resonance point, whereby the parasitic capacity of the PIN diode is canceled in the second band.

Claims

1. A dual band switch comprising:

a parallel circuit including

i) a diode; and

ii) a compensation circuit for said diode, said compensation circuit having at least two series resonance points and a parallel resonance point,

wherein said compensation circuit comprises a series circuit including a) a series resonance circuit including at least two elements and b) a parallel resonance circuit including at least two elements.

2. The dual band switch according to claim 1 further comprising:

a first terminal;

a second terminal;

a common terminal;

a further parallel circuit including

i) a further diode; and

ii) a further compensation circuit for said further diode, said further compensation circuit having at least two series resonance points and a parallel resonance point,

wherein said further compensation circuit comprises a further series circuit including a) a further series resonance circuit and b) a further parallel resonance circuit,

said further diode and said further compensation circuit are coupled between said second terminal and said common terminal, and

said diode and said compensation circuit are coupled between said first terminal and said common terminal.

3. The dual band switch according to claim 2, wherein said dual band switch is included in a dual band antenna of a duplexer which further comprises:

a combiner having a first sending side terminal, a second sending side terminal, and an output terminal; and

a divider having a first receiving side terminal, a second receiving side terminal, and an input terminal,

wherein said output terminal of said combiner is coupled to said first terminal of said dual band switch, and said input terminal of said divider is coupled to said second terminal of said dual band switch.

4. The dual band switch according to claim 3, wherein said combiner includes a low-pass filter which is coupled between said first sending side terminal and said output terminal, and a high-pass filter which is coupled between said second sending side terminal and said output terminal.

5. The dual band switch according to claim 3, wherein said combiner includes a low-pass filter which is coupled between said first sending side terminal and said output terminal, and a band-pass filter which is coupled between said second sending side terminal and said output terminal.

6. The dual band switch according to claim 3, wherein said divider includes a low-pass filter which is coupled between said input terminal and said first receiving side terminal, and a high-pass filter which is coupled between said input terminal and said second receiving side terminal.

7. The dual band switch according to claim 2, wherein said divider includes a band-pass filter which is coupled between said input terminal and said first receiving side terminal, and a band-pass filter which is coupled between said input terminal and said second receiving side terminal.

8. The dual band switch according to claim 2, wherein said further compensation circuit comprises a parallel circuit including i) a first series resonance circuit and ii) a second series resonance circuit.

9. The dual band switch according to claim 1, further comprising:

a first terminal;

a second terminal;

a common terminal;

said parallel circuit including said diode coupled between said first terminal and said common terminal,

a first series circuit including a first phase shift circuit and a second phase shift circuit, said first phase shift circuit is coupled between said common terminal and a middle node, and said second phase shift circuit is coupled between said middle node and said second terminal;

a second series circuit including a further diode and a further compensation circuit, said series circuit coupled between said middle node and a ground terminal; and

a third diode coupled between said second terminal and said ground terminal.

10. The dual band switch according claim 9, wherein said further compensation circuit has at least one parallel resonance point.

11. The dual band switch according to claim 9, wherein at a frequency at which a phase of said first phase shift circuit becomes substantially 90°

, a parasitic inductance of said second diode in an active state and said second compensation circuit attains a series resonance.

12. The dual band switch according to claim 9, wherein, at a frequency at which a total of a phase of said first phase shift circuit and a phase of said second phase shift circuit becomes substantially 90°

, said second compensation circuit attains a parallel resonance.

13. The dual band switch according to claim 1, wherein said dual band switch is included in a dual band mobile communication apparatus as a high frequency circuit for said dual band mobile communication apparatus.

14. A dual band switch comprising:

a parallel circuit including

i) a diode; and

ii) a compensation circuit for said diode, said compensation circuit having at least two series resonance points and a parallel resonance point,

wherein said compensation circuit comprises a series circuit including a) a series resonance circuit, said series resonance circuit including a capacitor and an inductor connected in series, and b) a parallel resonance circuit, said parallel resonance circuit including a capacitor and an inductor connected in parallel.