Switching device having a discharge circuit for improved intermodulation distortion performance

• US 8,975,950 B2
• Filed: 07/06/2013
• Issued: 03/10/2015
• Est. Priority Date: 07/07/2012
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Madan, Anuj, Altunkilic, Fikret, Blin, Guillaume Alexandre
• Primary Examiner(s): Wells, Kenneth B.
• Application Number:
  US13/936,173
• Publication Number:
  US 20140009205A1
• Time in Patent Office: 612 Days
• Field of Search: 327/434, 327436-437, 333/103
• US Class Current: 327/434
• CPC Class Codes: H01L 21/77 Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate electrically programmable read-only memories or multistep manufacturing processes therefor H10B69/00
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H03K 17/063 in field-effect transistor switches
• CPC Class Codes: H03K 17/162 without feedback from the output circuit to the control circuit
• CPC Class Codes: H03K 17/687 the devices being 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: H03K 2017/066 Maximizing the OFF-resistance instead of minimizing the ON-resistance
• CPC Class Codes: H03K 2217/0009 AC switches, i.e. delivering AC power to a load
• CPC Class Codes: H03K 2217/0018 Special modifications or use of the back gate voltage of a FET
• CPC Class Codes: H03K 2217/0036 Means reducing energy consumption
• 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

Radio-frequency (RF) switch circuits are disclosed providing improved switching performance. An RF switch system includes at least one field-effect transistor (FET) disposed between a first node and a second node, each having a respective source, drain, gate, and body. The system includes a coupling circuit including a first path and a second path, the first path being between the respective source or the respective drain and the respective gate of the at least one FET, the second path being between the respective source or the respective drain and the respective body of the at least one FET. The coupling circuit may be configured to allow discharge of interface charge from either or both of the coupled gate and body.

Claims

1. A radio-frequency (RF) switch comprising:

a field-effect transistor (FET) disposed between first and second nodes, the FET having a body and a gate; and

a coupling path connected between the body and gate, the coupling path including a resistor and a capacitor connected in series, such that the capacitor of the coupling path substantially blocks any and all DC current flow from the gate to the body and from the body to the gate.

2. The switch of claim 1 wherein the FET is a silicon-on-insulator (SOI) FET.

3. The switch of claim 1 wherein the coupling path consists of the capacitor and the resistor.

4. The switch of claim 3 wherein the capacitor and the resistor are selected to yield a desired intermodulation distortion (IMD) level of the switch, the desired IMD level being below a set threshold.

5. The switch of claim 1 further comprising a gate bias resistor connected in parallel with the gate and the coupling path.

6. The switch of claim 1 further comprising a body bias resistor connected in parallel with the body and the coupling path.

7. The switch of claim 1 wherein the first node is configured to receive an RF signal having a power value and the second node is configured to output the RF signal when the FET is in an ON state.

8. The switch of claim 7 further comprising N additional FETs connected in series with the FET, the quantity N selected to allow the switch circuit to handle the power value of the RF signal.

9. A method for fabricating a semiconductor die, the method comprising:

providing a semiconductor substrate;

forming a field-effect transistor (FET) on the semiconductor substrate, the FET having a gate and a body; and

forming a coupling circuit on the semiconductor substrate that is connected to the body and gate and includes a resistor and a capacitor connected in series, such that the capacitor of the coupling circuit substantially blocks any and all DC current flow from the gate to the body and from the body to the gate.

10. The method of claim 9 further comprising forming an insulator layer between the FET and the semiconductor substrate.

11. The method of claim 9 wherein the coupling circuit consists of the capacitor and the resistor.

12. A radio-frequency (RF) switch module comprising:

a packaging substrate configured to receive a plurality of components;

a semiconductor die mounted on the packaging substrate, the die including a field-effect transistor (FET); and

a coupling circuit that couples a body and a gate of the FET, the coupling circuit including a resistor and a capacitor connected in series, such that the capacitor of the coupling circuit substantially blocks any and all DC current flow from the gate to the body and from the body to the gate.

13. The switch module of claim 12 wherein the semiconductor die is a silicon-on-insulator (SOI) die.

14. The switch module of claim 12 wherein the coupling circuit consists of the capacitor and the resistor.

15. The switch module of claim 12 wherein the coupling circuit is part of the same semiconductor die as the FET.

16. The switch module of claim 12 wherein the coupling circuit is part of a second die mounted on the packaging substrate.

17. The switch module of claim 12 wherein the coupling circuit is disposed at a location outside of the semiconductor die.