High frequency switch

• US 6,917,258 B2
• Filed: 10/14/2003
• Issued: 07/12/2005
• Est. Priority Date: 10/24/2002
• 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: Nagata, Yasushi, Yasuho, Takeo, Kushitani, Hiroshi
• Primary Examiner(s): Summons, Barbara
• Application Number:
  US10/684,767
• Publication Number:
  US 20040121752A1
• Time in Patent Office: 637 Days
• Field of Search: 333/103, 333/104, 333/126, 333/129, 333/132, 333/133, 455/83
• US Class Current: 333/103
• CPC Class Codes: H01P 1/15 by semiconductor devices
• CPC Class Codes: H03K 17/6871 the output circuit comprising more than one controlled field-effect transistor
• CPC Class Codes: H03K 17/693 Switching arrangements with several input- or output-terminals, e.g. multiplexers, distributors logic circuits H03K19/00; code converters H03M5/00, H03M7/00
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 1/0298 Multilayer circuits
• CPC Class Codes: H05K 1/162 incorporating printed capacitors
• CPC Class Codes: H05K 1/181 associated with surface mounted components

Abstract

A high frequency switch configured particularly with FET switches. One end of second FET switch is connected between I/O port and reception port and the other end is ground. A parallel unit of strip line and capacitor is connected between second FET switch and I/O port. This parallel unit has the electrical length equivalent to ¼ wavelength of the high frequency signal input from transmission port.

Claims

1. A high frequency switch comprising:

a first FET switch connected between an input and output (I/O) port and a transmission port;

a second FET switch whose one end is connected between said I/O port and a reception port and the other end is ground;

said first FET switch and said second FET switch being a two-step structure;

a control port for controlling turning on and off of said first and second FET switches; and

a parallel unit of a strip line and capacitor, said parallel unit connected between one end of said second FET switch and said I/O port, and having an electrical length equivalent to about ¼

wavelength of a high frequency signal input from said transmission port.

2. The high frequency switch as defined in claim 1, wherein at least one end of said strip line is ground via a capacitor.

3. The high frequency switch as defined in claim 1, further including a reception filter coupled to said reception port by a capacitor which creates a capacitive coupling.

4. The high frequency switch as defined in claim 3, wherein said reception filter is a SAW filter.

5. A high frequency switch comprising:

a first FET switch connected between an input and output (I/O) port and transmission port;

a second FET switch whose one end is connected between said I/O port and a reception port and the other end is ground;

a control port for controlling turning on and off of said first FET switch and of said second FET switch; and

a parallel unit of a strip line and capacitor, said parallel unit connected between one end of said second FET switch and said I/O port, and having an electrical length equivalent to about ¼

wavelength of a high frequency signal input from said transmission port and a resonance frequency of said parallel unit is set to an image band region of the system.

6. A high frequency switch comprising:

a first FET switch connected between an input and output (I/O) port and transmission port;

a parallel unit of a strip line and capacitor, said parallel unit connected between said I/O port and a reception port, and having an electrical length equivalent to ¼

wavelength of a high frequency signal input from said transmission port;

a second FET switch whose one end is connected to said strip line to a side of said reception port and the other end is ground;

said first FET switch and said second FET switch being a two-step structure; and

a control port for controlling turning on and off of said first and second FET switches;

wherein said parallel unit of the strip line and capacitor is formed in an inner layer of a dielectric multilayer board, and said first and second FET switches are mounted on a surface of said multilayer board as a high frequency device.

7. The high frequency switch as defined in claim 6, wherein at least one end of said parallel unit of said strip line and said capacitor is ground via a grounding capacitor, said grounding capacitor being formed in an inner layer of said multilayer board.

8. The high frequency switch as defined in claim 6, wherein a transmission filter configured with an LC is connected to an end of said transmission port, said transmission filter being formed in an inner layer of said multilayer board.

9. The high frequency switch as defined in claim 6, wherein a SAW filter is connected to an end of said reception port, said SAW filter being mounted on the surface of said multilayer board.