Antenna switch

• US 20050079829A1
• Filed: 08/20/2004
• Published: 04/14/2005
• Est. Priority Date: 10/08/2003
• Status: Abandoned Application

• Current Assignee: Renesas Technology Corporation (Renesas Electronics Corporation)
• Original Assignee: Renesas Technology Corporation (Renesas Electronics Corporation)
• Inventors: Ogawa, Takashi, Nakajima, Akishige, Suenaga, Hidenori, Kondoh, Hiroshi
• Application Number:
  US10/921,815
• Publication Number:
  US 20050079829A1
• Time in Patent Office: Days
• US Class Current: 455/83
• 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

An antenna switch having a simple configuration and realizing high isolation between transmitting and receiving is provided. The antenna switch has a first switch connected between a transmitting terminal 31 and an antenna terminal 4, a transmission circuit 9 whose one end is connected to the antenna terminal and which shifts a phase of a transmitting signal by 90 degrees at use frequency, a second switch 6 whose one end is connected to the other end of the transmission circuit 9 and whose other end is grounded, and a plurality of third switches 7, 8 connected between the other end of the transmission circuit 9 and the plurality of receiving terminals 32, 33.

Claims

1. An antenna switch for selectively connecting any of a transmitting terminal to which a transmitted signal is inputted and a plurality of receiving terminals from which received signals are outputted to an antenna terminal, comprising:

a first switch connected between said transmitting terminal and said antenna terminal;

a transmission circuit whose one end is connected to said antenna terminal and from whose other end a transmitted signal whose phase is shifted by desired degrees is obtained at use frequency;

a second switch whose one end is connected to said other end of said transmission circuit and whose other end is grounded in alternate current; and

a plurality of third switches connected between said other end of said transmission circuit and said plurality of receiving terminals.

2. The antenna switch according to claim 1, wherein said first to third switches are constructed by HEMT devices.

3. The antenna switch according to claim 1, further comprising a fourth switch whose one end is connected to each of said plurality of receiving terminals and whose other end is grounded.

4. An antenna switch comprising:

two sub antenna switches for selecting connecting any of a transmitting terminal to which a transmitted signal is inputted and a plurality of receiving terminals from which received signals are outputted to a sub antenna terminal; and

a diplexer connected between an antenna terminal and said two sub antenna terminals,

each of said sub antenna switches comprising;

a first switch connected between said transmitting terminal and said sub antenna terminal;

a transmission circuit whose one end is connected to said sub antenna terminal and from whose other end a transmitted signal whose phase is shifted by desired degrees is obtained at use frequency;

a second switch whose one end is connected to said other terminal of said transmission circuit and whose other end is grounded in alternate current; and

a plurality of third switches connected between said other end of said transmission circuit and said plurality of receiving terminals.

5. An antenna switch for selectively connecting any of a transmitting terminal to which a transmitted signal is inputted and a plurality of receiving terminals from which received signals are outputted to an antenna terminal, comprising,:

a first switch connected between said transmitting terminal and said antenna terminal;

a seconds witch whose one end is connected to said antenna terminal and whose other end is coupled to selected one of said plurality of receiving terminals; and

a plurality of third switches each inserted in a coupling path between said other end of said second switch and each of said plurality of receiving terminals.

6. The antenna switch according to claim 5, wherein said first to third switches are constructed by HEMT devices.

7. The antenna switch according to claim 6, wherein a handling voltage of said second switch is higher than that of said third switch.

8. The antenna switch according to claim 5, further comprising a fourth switch whose one end is connected to said other end of said second switch and whose other end is grounded in alternate current.

9. The antenna switch according to claim 5, further comprising a fifth switch connected between another transmitting terminal and said antenna terminal.

10. The antenna switch according to claim 9, wherein said first to third switches and said fifth switch are constructed by HEMT devices, and a handling voltage of said first, second and fifth switches is higher than that of said third switch.

11. The antenna switch according to claim 5, wherein said second switch is a high handling voltage switch constructed by a plurality of transistors in which switch current paths are connected in series.

12. An RF module comprising:

an antenna switch; and

at least one of a transmitting circuit and a receiving circuit,

wherein said antenna switch selectively connects any of a transmitting terminal to which a transmitted signal is inputted and a plurality of receiving terminals from which received signals are outputted to an antenna terminal, and comprises;

a first switch connected between said transmitting terminal and said antenna terminal;

a second switch whose one end is connected to said antenna terminal and whose other end is coupled to selected one of said plurality of receiving terminals; and

a plurality of third switches each inserted in a coupling path between said other end of said second switch and each of said plurality of receiving terminals.

13. The RF module according to claim 12, wherein said first to third switches are constructed by HEMT devices.

14. The RF module according to claim 13, wherein a handling voltage of said second switch is higher than that of said third switch.

15. The RF module according to claim 12, further comprising a fourth switch whose one end is connected to said other end of said second switch and whose other end is grounded in alternate current.

16. The RF module according to claim 12, further comprising a fifth switch connected between another transmitting terminal and said antenna terminal.

17. The RF module according to claim 16, wherein said first to third switches and said fifth switch are constructed by HEMT devices, and a handling voltage of said first, second, and fifth switches is higher than that of said third switch.

18. The RF module according to claim 12, wherein said second switch is a high handling voltage switch constructed by a plurality of transistors in which switch current paths are connected in series.