Radio-frequency switch system having improved intermodulation distortion performance

• US 9,148,194 B2
• Filed: 07/06/2013
• Issued: 09/29/2015
• 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): NGUYEN, TUAN HOANG
• Application Number:
  US13/936,175
• Publication Number:
  US 20140011463A1
• Time in Patent Office: 815 Days
• Field of Search: 455/78, 455/87, 455/252.1, 455/296, 438/178, 438/197, 438/381, 327/427, 327/434, 327/436, 327/437
• US Class Current: 1/1
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body
• CPC Class Codes: H01L 27/0629 in combination with diodes, or resistors, or capacitors
• 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 17/687 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 2217/0018 Special modifications or use of the back gate voltage of a FET
• CPC Class Codes: H03K 2217/0054 Gating switches, e.g. pass gates
• CPC Class Codes: H04B 1/44 Transmit/receive switching
• 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 a switch having a stack of field-effect transistors (FETs) connected in series between first and second nodes. A capacitor connected in series with the switch is configured to inhibit a low-frequency blocker signal from mixing with a fundamental-frequency signal in the switch.

Claims

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

a first switch circuit connected between an antenna node and a transmit node;

a second switch circuit connected between the antenna node and a receive node;

a first capacitor connected in series with the first switch circuit between the first switch circuit and the antenna node;

a second capacitor connected in series with the second switch circuit between the second switch circuit and the antenna node;

a first shunt arm connected to the first switch circuit and the transmit node, the first shunt arm including a third switch circuit connected to ground; and

a second shunt arm connected to the second switch circuit and the receive node, the second shunt arm including a fourth switch circuit connected to ground.

2. The switch system of claim 1 wherein at least one of the first and second capacitors is configured to inhibit a low-frequency blocker signal from mixing with a fundamental-frequency signal in the switch.

3. The switch system of claim 1 wherein the first shunt arm includes a third capacitor connected between the third switch circuit and the transmit node, and the second shunt arm includes a fourth capacitor connected between the fourth switch circuit and the receive node.

4. A radio-frequency (RF) switch system comprising:

a first switch circuit connected between an antenna node and a transmit node;

a second switch circuit connected between the antenna node and a receive node;

a first capacitor connected in series with the first switch circuit between the first switch circuit and the antenna node;

a second capacitor connected in series with the second switch circuit between the second switch circuit and the antenna node;

a first shunt arm connected to the first switch circuit and the transmit node, the first shunt arm including a third switch circuit connected to ground and a third capacitor connected between the third switch circuit and the transmit node.

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

providing a semiconductor substrate;

forming a first switch circuit on the semiconductor substrate so as to be connected between an antenna node and a transmit node;

forming a second switch circuit on the semiconductor substrate so as to be connected between the antenna node and a receive node;

forming a first capacitor on the semiconductor substrate so as to be connected in series with the first switch circuit between the first switch circuit and the antenna node;

forming a second capacitor on the semiconductor substrate so as to be connected in series with the second switch circuit between the second switch circuit and the antenna node;

forming a first shunt arm connected to the first switch circuit and the transmit node, the first shunt arm including a third switch circuit connected to ground; and

forming a second shunt arm connected to the second switch circuit and the receive node, the second shunt arm including a fourth switch circuit connected to ground.

6. The method of claim 5 further comprising forming an insulator layer between the first switch circuit and the semiconductor substrate.

7. 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 first switch circuit connected between an antenna node and a transmit node and a second switch circuit connected between the antenna node and a receive node;

a first capacitor connected in series with the first switch circuit between the first switch circuit and the antenna node;

a second capacitor connected in series with the second switch circuit between the second switch circuit and the antenna node;

a first shunt arm connected to the first switch circuit and the transmit node, the first shunt arm including a third switch circuit connected to ground; and

a second shunt arm connected to the second switch circuit and the receive node, the second shunt arm including a fourth switch circuit connected to ground.

8. The switch module of claim 7 wherein at least one of the first and second capacitors is configured to inhibit a low-frequency blocker signal from mixing with a fundamental-frequency signal in the switch.

9. The switch module of claim 7 wherein the first capacitor is part of the same semiconductor die as the first switch circuit.

10. The switch module of claim 7 wherein the first capacitor is part of a second die mounted on the packaging substrate.

11. The switch module of claim 7 wherein the first capacitor is disposed at a location outside of the semiconductor die.