Switch device and portable communication terminal

• US 20030181167A1
• Filed: 09/26/2002
• Published: 09/25/2003
• Est. Priority Date: 02/19/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Iida, Sachio
• Granted Patent: US 6,999,786 B2
• Time in Patent Office: Days
• US Class Current: 455/78
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/006 using switches for selecting the desired band H04B1/0057 takes precedence
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• 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

Abstract

There is provided a small-sized switch apparatus for switching between signal paths of at least a first, second and third frequency bands, which is capable of handling high-powered high-frequency signals with a relatively low control voltage, and also a mobile terminal apparatus employing this. A first signal terminal of a diplexer (1) is connected to an antenna terminal T_ant, and a second signal terminal is connected to a high-frequency switch (4) via a filter (2). A third signal terminal of the diplexer is connected to a high-frequency switch (50) via a filter (3). The high-frequency switch (4) has PIN diodes D1 and D2 as switching devices, and performs switching between a GSM transmission signal and a GSM reception signal. The high-frequency switch (50) has three sets of serially connected multi-staged FETs (31) through (33), (21) through (23) and (31) through (33) as switching devices, and performs switching between WCDMA transmission/reception signals, a DCS transmission signal and a DCS reception signal.

Claims

1. A switch apparatus for switching between signal paths of at least a first, second and third frequency bands, wherein said switch apparatus is characterized by comprising:

a diplexer having a first signal terminal which is a transmission/reception signal terminal shared by said signals of at least said first, second and third frequency bands, a second signal terminal for outputting a signal of said first frequency band separated from a received signal, a third signal terminal for outputting the remaining signal after said signal of said first frequency band is separated, wherein said received signal inputted to said first signal terminal is divided between said second and third signal terminals, and transmission signals to be inputted to said second and third signal terminals are combined and outputted to said first signal terminal;

a first high-frequency switch connected to said second signal terminal of said diplexer; and

a second high-frequency switch connected to said third signal terminal of said diplexer, wherein

said first high-frequency switch has a plurality of switching means respectively configured with diodes, and selectively switches between two signal terminals to be connected to said second signal terminal of said diplexer, and

said second high-frequency switch has at least three switching means respectively configured with FETs, and selectively switches between at least three signal terminals to be connected to said third signal terminal of said diplexer.

2. The switch apparatus according to claim 1, characterized in that each switching means of said second high-frequency switch includes a plurality of serially connected FETs.

3. The switch apparatus according to claim 1 or 2, characterized in that said signals of said first, second and third frequency bands are GSM, WCDMA and DCS signals, respectively.

4. The switch apparatus according to claim 3, characterized in that said first high-frequency switch has PIN diodes as said switching means and performs switching between a GSM transmission signal and a GSM reception signal, and said second high-frequency switch has three sets of serially connected multi-staged FETs as said switching means, and performs switching between WCDMA transmission/reception signals, a DCS transmission signal and a DCS reception signal.

5. A mobile communications terminal apparatus, characterized by being configured such that said first signal terminal of said diplexer of the switch apparatus according to one of claims 1 through 4 is connected to an antenna, a transmission/reception circuit for said signal of said first frequency band is connected to said two signal terminals of said first high-frequency switch, and a transmission/reception circuit for said signals of said second and third frequency bands is connected to said at least three signal terminals of said second high-frequency switch.