RF SWITCH IMPLEMENTATION IN CMOS PROCESS

• US 20130244595A1
• Filed: 09/21/2010
• Published: 09/19/2013
• Est. Priority Date: 09/21/2010
• Status: Active Grant

• Current Assignee: DSP Group Ltd. (Synaptics Incorporated)
• Original Assignee: DSP Group Ltd. (Synaptics Incorporated)
• Inventors: Hasson, Yaron, Mostov, Alex
• Granted Patent: US 9,136,838 B2
• Time in Patent Office: Days
• US Class Current: 455/78
• CPC Class Codes: H03K 17/6872 using complementary field-effect transistors
• 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 1/44 Transmit/receive switching
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver

Abstract

A dual pole dual through switch for switching between at least four states. The switch comprises four transistors such as N-channel Metal Oxide Semiconductor transistors, such that at each state at most one transistor is in “on” state, and the others are in “off” state. Each transistor has its own control circuit, which provides zero or negative voltage to the drain of the transistor, positive voltage to the source of the transistor, and control alternating voltage to the gate of the transistor. The switch can be used on-chip for devices. Such devices may include a base station or a handset of a cordless phone.

Claims

1. A switch for selecting between four options, the switch comprising at least four transistors, wherein at any time at most one transistor is in “

on”

state, wherein the switch is an on-chip switch.

2. The switch of claim 1 wherein the switch is a dual pole dual through switch.

3. The switch of claim 1 wherein the switch is used in a base station of a cordless phone.

4. The switch of claim 2 wherein the switch selects between two antennas and between transmitting and receiving states.

5. The switch of claim 1 wherein at least one of the at least four transistors is an N-channel Metal Oxide Semiconductor (NMOS) transistor.

6. The switch of claim 1 further comprising at least one control circuit providing voltage to at least one of the at least four transistors.

7. The switch of claim 6 wherein the control circuit comprises:

components for providing zero or negative voltage to the drain of the at least one transistor;

components for providing positive voltage to the source of the at least one transistor; and

components for providing alternating voltage to the gate of the at least one transistor.

8. The switch of claim 1 wherein at least one of the at least four transistors is an N-channel Metal Oxide Semiconductor.

9. A wireless communication device having a handset and a base station, the base station comprising:

a first antenna and a second antenna, each of the first antenna and the second antenna operative to transmit and receive data; and

a switch for operating the first or the second antenna, in transmitting or receiving mode, the switch comprising four transistors, each of the four transistor having its own control circuit, the switch located on a chip of the base station.

10. The wireless communication device of claim 9 wherein the handset comprises a switch having four transistors, the switch located on a chip of the handset.