Modulation Circuit and Semiconductor Device Including the Same

• US 20100087222A1
• Filed: 10/02/2009
• Published: 04/08/2010
• Est. Priority Date: 10/03/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamashita, Yukiko, Nishijima, Tatsuji
• Granted Patent: US 8,948,696 B2
• Time in Patent Office: Days
• US Class Current: 455/550.100
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: H04L 27/04 Modulator circuits; Transmitter circuits

Abstract

An object of the present invention is to reduce the power consumption of a modulation circuit. The modulation circuit includes a load, a diode, and a transistor. An anode of the diode is electrically connected to one terminal of an antenna via the load; a cathode of the diode is electrically connected to one of a source and a drain of the transistor; the other of the source and the drain of the transistor is electrically connected to the other terminal of the antenna; and the transistor is controlled to be turned on or off in accordance with a signal input to a gate of the transistor.

Claims

1. A semiconductor device comprising an antenna and a modulation circuit;

wherein the modulation circuit comprises a load, a diode and a switch; and

wherein the load, the diode and the switch are connected in series between two terminals of the antenna.

7. The modulation circuit according to claim 1, wherein the diode is formed over a flexible substrate.

13. The modulation circuit according to claim 1, wherein the diode is a diode-connected transistor.

19. A semiconductor device according to claim 1, further comprising:

a rectifier circuit, a demodulation circuit, a constant voltage circuit, and a logic circuit.

25. A cellular phone comprising the semiconductor device according to claim 1.

31. A personal computer comprising the semiconductor device according to claim 1.

2. A semiconductor device comprising an antenna and a modulation circuit;

wherein the modulation circuit comprises a load, a diode and a transistor;

wherein the load, the diode and the transistor are connected in series between two terminals of the antenna; and

wherein the transistor is controlled to be turned on or off in accordance with a signal input to a gate of the transistor.

8. The modulation circuit according to claim 2, wherein the diode is formed over a flexible substrate.

14. The modulation circuit according to claim 2, wherein the diode is a diode-connected transistor.

20. A semiconductor device according to claim 2, further comprising:

a rectifier circuit, a demodulation circuit, a constant voltage circuit, and a logic circuit.

26. A cellular phone comprising the semiconductor device according to claim 2.

32. A personal computer comprising the semiconductor device according to claim 2.

3. A semiconductor device comprising an antenna and a modulation circuit;

wherein the modulation circuit comprises a resistor, a diode, and a switch and

wherein the resistor, the diode and the switch are connected in series between two terminals of the antenna.

9. The modulation circuit according to claim 3, wherein the diode is formed over a flexible substrate.

15. The modulation circuit according to claim 3, wherein the diode is a diode-connected transistor.

21. A semiconductor device according to claim 3, further comprising:

a rectifier circuit, a demodulation circuit, a constant voltage circuit, and a logic circuit.

27. A cellular phone comprising the semiconductor device according to claim 3.

33. A personal computer comprising the semiconductor device according to claim 3.

4. A semiconductor device comprising an antenna and a modulation circuit;

wherein the modulation circuit comprises a resistor, a diode, and a transistor;

wherein the resistor, the diode and the transistor are connected in series between two terminals of the antenna; and

wherein the transistor is controlled to be turned on or off in accordance with a signal input to a gate of the transistor.

10. The modulation circuit according to claim 4, wherein the diode is formed over a flexible substrate.

16. The modulation circuit according to claim 4, wherein the diode is a diode-connected transistor.

22. A semiconductor device according to claim 4, further comprising:

a rectifier circuit, a demodulation circuit, a constant voltage circuit, and a logic circuit.

28. A cellular phone comprising the semiconductor device according to claim 4.

34. A personal computer comprising the semiconductor device according to claim 4.

5. A semiconductor device comprising an antenna and a modulation circuit;

wherein the modulation circuit comprises a capacitor, a diode, and a switch; and

wherein the capacitor, the diode and the switch are connected in series between two terminals of the antenna.

11. The modulation circuit according to claim 5, wherein the diode is formed over a flexible substrate.

17. The modulation circuit according to claim 5, wherein the diode is a diode-connected transistor.

23. A semiconductor device according to claim 5, further comprising:

a rectifier circuit, a demodulation circuit, a constant voltage circuit, and a logic circuit.

29. A cellular phone comprising the semiconductor device according to claim 5.

35. A personal computer comprising the semiconductor device according to claim 5.

6. A semiconductor device comprising an antenna and a modulation circuit;

wherein the modulation circuit comprises a capacitor, a diode, and a transistor,

wherein the diode, the capacitor and the transistor are connected in series between two terminals of the antenna; and

wherein the transistor is controlled to be turned on or off in accordance with a signal input to a gate of the transistor.

12. The modulation circuit according to claim 6, wherein the diode is formed over a flexible substrate.

18. The modulation circuit according to claim 6, wherein the diode is a diode-connected transistor.

24. A semiconductor device according to claim 6, further comprising:

a rectifier circuit, a demodulation circuit, a constant voltage circuit, and a logic circuit.

30. A cellular phone comprising the semiconductor device according to claim 6.

36. A personal computer comprising the semiconductor device according to claim 6.