Antenna switch circuit with improved harmonic suppression characteristic

• US 10,050,609 B2
• Filed: 08/30/2017
• Issued: 08/14/2018
• Est. Priority Date: 10/05/2016
• Status: Active Grant

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Yoo, Hyun Jin, Kim, Yoo Hwan, Na, Yoo Sam, Lim, Jong Mo, Yoo, Hyun Hwan
• Primary Examiner(s): Wells, Kenneth B
• Application Number:
  US15/691,167
• Publication Number:
  US 20180097511A1
• Time in Patent Office: 349 Days
• CPC Class Codes: H01P 1/213 combining or separating two or more different frequencies H01P1/215 takes precedence
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H03H 11/04 Frequency selective two-port networks
• CPC Class Codes: H03K 5/1252 Suppression or limitation of noise or interference specially adapted for transmission systems H04B15/00, H04L25/08
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04B 1/44 Transmit/receive switching

Abstract

An antenna switch circuit includes: a first switch circuit connected between a first signal port for signal transmission and reception and an antenna port, and operated by a first gate signal; and a second switch circuit connected between a second signal port for signal transmission and reception and the antenna port, and operated by a second gate signal. The first switch circuit and/or the second switch circuit includes a first transistor and a second transistor connected in series between the first and second signal ports, a first voltage dividing circuit including a first resistor and a second resistor connected in series between a source and a drain of the first transistor, and a first variable capacitor circuit connected between the first voltage dividing circuit and a body of the first transistor, and having capacitance varying according to a voltage across opposite ends of the first variable capacitor circuit.

Claims

1. An antenna switch circuit, comprising:

a first switch circuit connected between a first signal port for signal transmission and reception and an antenna port, and configured to be operated by a first gate signal; and

a second switch circuit connected between a second signal port for signal transmission and reception and the antenna port, and configured to be operated by a second gate signal,

wherein either one or both of the first switch circuit and the second switch circuit comprises

a first transistor and a second transistor connected in series between the first and second signal ports,

a first voltage dividing circuit comprising a first resistor and a second resistor connected in series between a source of the first transistor and a drain of the first transistor, and

a first variable capacitor circuit connected between the first voltage dividing circuit and a body of the first transistor, and comprising capacitance varying according to a voltage across opposite ends of the first variable capacitor circuit.

2. The antenna switch circuit of claim 1, wherein the either one or both of the first switch circuit and the second switch circuit further comprises

a second voltage dividing circuit comprising a third resistor and a fourth resistor connected in series between a source of the second transistor and a drain of the second transistor, and

a second variable capacitor circuit connected between the second voltage dividing circuit and a body of the second transistor, and comprising capacitance varying according to a voltage across opposite ends of the second variable capacitor circuit.

3. The antenna switch circuit of claim 2, wherein

the first variable capacitor circuit comprises a first variable capacitor connected between a first connection node, located between the first resistor and the second resistor, and a body node of the first transistor, and

the first variable capacitor comprises capacitance varying according to a magnitude of a voltage between the first connection node and the body node of the first transistor.

4. The antenna switch circuit of claim 3, wherein the first variable capacitor comprises a varactor diode.

5. The antenna switch circuit of claim 2, wherein

the first variable capacitor circuit comprises

a first variable capacitor connected between a first connection node, located between the first resistor and the second resistor, and a body node of the first transistor, and

a second variable capacitor connected between an end of the second resistor, opposite the first connection node, and the body node of the first transistor,

the first variable capacitor comprises capacitance varying according to a magnitude of a voltage between the first connection node and the body node of the first transistor, and

the second variable capacitor comprises capacitance varying according to a magnitude of a voltage between the end of the second resistor and the body node of the first transistor.

6. The antenna switch circuit of claim 2, wherein

the second variable capacitor circuit comprises a first variable capacitor connected between a third connection node, located between the third resistor and the fourth resistor, and a body node of the second transistor, and

the first variable capacitor comprises capacitance varying according to a magnitude of a voltage between the third connection node and the body node of the second transistor.

7. The antenna switch circuit of claim 2, wherein

the second variable capacitor circuit comprises

a first variable capacitor connected between a third connection node, located between the third resistor and the fourth resistor, and a body node of the second transistor, and

a second variable capacitor connected between an end of the fourth resistor, opposite the third connection node, and the body node of the second transistor,

the first variable capacitor comprises capacitance varying according to a magnitude of a voltage between the third connection node and the body node of the second transistor, and

the second variable capacitor comprises capacitance varying according to a magnitude of a voltage between the end of the fourth resistor and the body node of the second transistor.

8. The antenna switch circuit of claim 2, wherein

the second resistor is connected to a connection node of the first and second transistors, and comprises a resistance value that is less than a resistance value of the first resistor, and

the third resistor is connected to the connection node of the first and second transistors, and comprises a resistance value that is less than a resistance value of the fourth resistor.

9. The antenna switch circuit of claim 2, wherein

the second resistor is connected to a connection node of the first and second transistors, and comprises a resistance value that is greater than a resistance value of the first resistor, and

the third resistor is connected to the connection node of the first and second transistors, and comprises a resistance value that is greater than a resistance value of the fourth resistor.

10. An antenna switch circuit, comprising:

a first switch circuit connected between a first signal port for signal transmission and reception and an antenna port, and configured to be operated by a first gate signal;

a second switch circuit connected between a second signal port for signal transmission and reception and the antenna port, and configured to be operated by a second gate signal;

a first shunt circuit connected in series between the first signal port and a first ground port, and configured to be switched by a third gate signal together with the first switch circuit; and

a second shunt circuit connected in series between the second signal port and a second ground port, and configured to be switched by a fourth gate signal together with the second switch circuit,

wherein any one or any combination of any two or more of the first switch circuit, the second switch circuit, the first shunt circuit, and the second shunt circuit comprises

a first transistor and a second transistor connected in series between the first and second signal ports,

a first voltage dividing circuit comprising a first resistor and a second resistor connected in series between a source of the first transistor and a drain of the first transistor, and

a first variable capacitor circuit connected between the first voltage dividing circuit and a body of the first transistor, and comprising capacitance varying according to a voltage across opposite ends of the first variable capacitor circuit.

11. The antenna switch circuit of claim 10, wherein the any one or any combination of any two or more of the first switch circuit, the second switch circuit, the first shunt circuit, and the second shunt circuit comprises

a second voltage dividing circuit comprising a third resistor and a fourth resistor connected in series between a source of the second transistor and a drain of the second transistor, and

a second variable capacitor circuit connected between the second voltage dividing circuit and a body of the second transistor, and comprising capacitance varying according to a voltage across opposite ends of the second variable capacitor circuit.

12. The antenna switch circuit of claim 11, wherein

the first variable capacitor circuit comprises a first variable capacitor connected between a first connection node, located between the first resistor and the second resistor, and a body node of the first transistor, and

the first variable capacitor comprises capacitance varying according to a magnitude of a voltage between the first connection node and the body node of the first transistor.

13. The antenna switch circuit of claim 12, wherein the first variable capacitor comprises a varactor diode.

14. The antenna switch circuit of claim 11, wherein

the first variable capacitor circuit comprises

a first variable capacitor connected between a first connection node, located between the first resistor and the second resistor, and a body node of the first transistor, and

a second variable capacitor connected between an end of the second resistor, opposite the first connection node, and the body node of the first transistor,

the first variable capacitor comprises capacitance varying according to a magnitude of a voltage between the first connection node and the body node of the first transistor, and

the second variable capacitor comprises capacitance varying according to a magnitude of a voltage between the end of the second resistor and the body node of the first transistor.

15. The antenna switch circuit of claim 11, wherein

the second variable capacitor circuit comprises a first variable capacitor connected between a third connection node, located between the third resistor and the fourth resistor, and a body node of the second transistor, and

the first variable capacitor comprises capacitance varying according to a magnitude of a voltage between the third connection node and the body node of the second transistor.

16. The antenna switch circuit of claim 11, wherein

the second variable capacitor circuit comprises

a first variable capacitor connected between a third connection node, located between the third resistor and the fourth resistor, and a body node of the second transistor, and

a second variable capacitor connected between an end of the fourth resistor, opposite the third connection node, and the body node of the second transistor,

the first variable capacitor comprises capacitance varying according to a magnitude of a voltage between the third connection node and the body node of the second transistor, and

the second variable capacitor comprises capacitance varying according to a magnitude of a voltage between the end of the fourth resistor and the body node of the second transistor.

17. The antenna switch circuit of claim 11, wherein

the second resistor is connected to a connection node of the first and second transistors, and comprises a resistance value that is less than a resistance value of the first resistor, and

the third resistor is connected to the connection node of the first and second transistors, and comprises a resistance value that is less than a resistance value of the fourth resistor.

18. The antenna switch circuit of claim 11, wherein

the second resistor is connected to a connection node of the first and second transistors, and comprises a resistance value that is greater than a resistance value of the first resistor, and

the third resistor is connected to the connection node of the first and second transistors, and comprises a resistance value that is greater than a resistance value of the fourth resistor.