Electronic device having an operating mode and an energy saving standby mode, and a method for switching between the two modes

• US 6,920,342 B2
• Filed: 06/17/2002
• Issued: 07/19/2005
• Est. Priority Date: 12/16/1999
• Status: Expired due to Term

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Reiner, Robert
• Primary Examiner(s): Trinh, Sonny
• Assistant Examiner(s): PHAN, HUY Q
• Application Number:
  US10/174,059
• Publication Number:
  US 20020169009A1
• Time in Patent Office: 1,128 Days
• Field of Search: 455/574, 455/343.2, 455/127.5, 455/68, 455/69, 370/311, 340/7.33, 340/7.36
• US Class Current: 455/574
• CPC Class Codes: H04B 1/1615 Switching on; Switching off, e.g. remotely battery saving circuits associated with selective call operation H04W52/00; details of power consumption reduction in a PLL, H03L7/0802, H03L7/14, H03L2207/08, H03L2207/18; muting amplifiers by gain control see H03G3/34
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

An electronic device has an operating mode and an energy saving standby mode. The electronic device includes an input-side antenna element for receiving a signal carrying information, a receiving unit for processing the basic information carried on the signal, a voltage supply unit for providing the supply voltage required for operation, and a switching unit for switching between the operating mode and the standby mode. First, to minimize the current being drawn in the standby mode, and second to ensure quick and reliable switching from the energy saving standby mode to the operating mode as required, it is proposed that the signal carrying the information includes a number of modulated frequency bands. At least one frequency band is intended for the basic information to be processed by the receiving unit. The other frequency band contains wake-up information for actuating the switching unit.

Claims

1. An electronic device, comprising:

an antenna element for receiving a signal carrying information, the signal carrying the information including at least a first modulated frequency band for carrying basic information and a second modulated frequency band for carrying wake-up information;

a receiving unit for processing the basic information carried on the signal, said receiving unit having an operating mode and an energy saving standby mode;

a voltage supply unit for providing a supply voltage required for operation; and

a switching unit for switching between the operating mode and the standby mode, said switching unit being actuated by the wake-up information.

2. The electronic device according to claim 1, comprising:

a filter unit connected downstream from said antenna unit, said filter unit separating the second frequency band carrying the wake-up information from the signal carrying the information; and

a demodulation unit obtaining the second frequency band from said filter unit, said demodulation unit demodulating the wake-up information;

said demodulation unit being at least partially passive and actuating said switching unit.

3. The electronic device according to claim 2, wherein said demodulation unit is as passive as possible.

4. The electronic device according to claim 2, wherein:

said filter element is also designed for separating the first frequency band carrying the basic information from the signal carrying the information.

5. The electronic device according to claim 2, wherein:

said filter unit is SAW filter.

6. The electronic device according to claim 1, wherein:

the wake-up information is processed by chirp compression to increase a magnitude of pulses in the second frequency band.

7. The electronic device according to claim 1, wherein:

the wake-up information is modulated to be in a form selected from the group consisting of a single pulse and a pulse sequence.

8. The electronic device according to claim 1, wherein:

in order to distinguish the wake-up information from disturbances, the wake-up information is a pulse sequence having a pulse repetition frequency;

said demodulation unit being designed in as a passive tuned circuit being tuned to the pulse repetition frequency in order to filter out the pulse sequence.

9. The electronic device according to claim 1, wherein:

the second frequency band carrying the wake-up information is a standardized, generally usable frequency band in a band range from 869.4 MHz to 869.65 MHz.

10. The electronic device according to claim 1, wherein:

the first frequency band carrying the basic information is a standardized frequency band for transmitting at a transmission power level of up to 5 mW in a band range from 869.7 MHz to 870.0 MHz.

11. The electronic device according to claim 1, wherein:

said voltage supply unit is a battery selected from the group consisting of a disposable battery and a rechargeable battery.

12. The electronic device according to claim 1, wherein said antenna element is matched to a nature of the signal carrying the information.

13. The electronic device according to claim 12, wherein said antenna element is in a form selected from the group consisting of a dipole, a coil, a capacitor plate, and a photoelement.

14. A method for switching from an energy saving standby mode to an operating mode, which comprises:

receiving a signal having a plurality of modulated frequency bands and carrying information;

filtering the signal to obtain a first frequency band for carrying basic information and a second frequency band for carrying wake-up information;

demodulating the second frequency band to obtain the wake-up information;

waking up from the standby mode to the operating mode when the second frequency band contains the wake-up information, and subsequently processing the basic information carried in the first frequency band; and

remaining in the standby mode for as long as no wake-up information is being carried by the second frequency band.

15. The method according to claim 14, which comprises:

switching from the standby mode to the operating mode.