Electronic device comprising an operating mode switching unit

• US 8,958,766 B2
• Filed: 01/14/2013
• Issued: 02/17/2015
• Est. Priority Date: 05/17/2010
• Status: Active Grant

• Current Assignee: Endiio Engineering GmbH
• Original Assignee: Smartexergy WMS GmbH
• Inventors: Ostertag, Thomas, Ungan, Tolgay, Gamm, Gerd Ulrich, Reindl, Leonhard Michael, Sippel, Matthias, Wendt, Thomas
• Primary Examiner(s): LE, NHAN T
• Application Number:
  US13/740,435
• Publication Number:
  US 20130130636A1
• Time in Patent Office: 764 Days
• Field of Search: 455 78- 83, 455/127, 455/129, 455/230, 455/232.1, 455/234.1, 455/248.1, 455/295, 455/313, 455/334
• US Class Current: 455/230
• CPC Class Codes: H04B 1/16 Circuits
• 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 appliance comprising an electrical circuit and an operating mode switching unit which can be awakened out of a sleep state into a working state in which the current consumption of the circuit is greater in than in the sleep state. To receive a radio signal, the appliance has a receiver comprising a UHF carrier that is amplitude-modulated by a modulation signal. The receiver comprises a UHF antenna connected to a passive filter stage to an input of a passive rectifier circuit. An output of the rectifier circuit is connected to a detector for the modulation signal. To wake the electrical circuit from the sleep state, the operating mode switching unit has a control connection to the detector. The appliance has a low current draw in the sleep state by matching the output impedance of the rectifier circuit to the input impedance of the detector.

Claims

1. An electronic appliance (1) having an electrical circuit and an operating mode switching device (18) which is associated with the latter and which can be used to wake the electrical circuit from a quiescent state into an operating state in which the current draw of the electrical circuit is greater than in the quiescent state, having a receiver for receiving a radio signal which has a UHF carrier which has been subjected to amplitude modulation with a modulation signal, wherein the receiver has a UHF antenna (6) which is connected to an input of a passive rectifier circuit (8) via a passive filter stage (7), wherein an output of the passive rectifier circuit (8) is connected to a detection device (16) for the modulation signal, and wherein the operating mode switching device (18) has a control connection to the detection device (16) for the purpose of waking the electrical circuit which is in the quiescent state, the improvement which comprises:

means for matching the output impedance of the rectifier circuit (8) to the input impedance of the detection device (16),

wherein the means for matching the output impedance of the rectifier circuit (8) to the input impedance of the detection device (16) includes a passive filter (9) operatively arranged between the output of the passive rectifier circuit (8) and the input of the detection device (16) for passing the modulation signal, and the passive filter stage (7) and/or the passive filter (9) has/have an LC resonant circuit including a quartz oscillator (12) and/or a microacoustic resonator.

2. The electronic appliance (1) as claimed in claim 1, wherein the passive filter (9) passes a modulation signal, the frequency range of which is between 10 kHz and 1.3 MHz.

3. The electronic appliance (1) of claim 2, wherein the passive filter (9) passes a modulation signal, the frequency of which is particularly above 30 kHz.

4. The electronic appliance (1) of claim 3, wherein the passive filter (9) passes a modulation signal, the frequency of which is preferably above 100 kHz.

5. The electronic appliance (1) as claimed in claim 1, wherein the LC resonant circuit has a capacitance (13) which is connected in series with the quartz oscillator (12) and/or the microacoustic resonator in a current path which connects the UHF antenna (6) to a connection for a constant potential, and in that the quartz oscillator (12) and/or the microacoustic resonator and the capacitance (13) are connected to a node (17) which is connected to the input of the rectifier circuit (8).

6. The electronic appliance (1) as claimed in claim 1, wherein the LC resonant circuit has a capacitance (13) which is connected in series with the quartz oscillator (12) and/or the microacoustic resonator in a current path which connects the output of the passive rectifier circuit (8) to a connection for a constant potential, and in that the quartz oscillator (12) and/or the microacoustic resonator and the capacitance (13) are connected to a node (15) to which the detection device (16) is connected.

7. The electronic appliance (1) as claimed in claim 1, wherein the LC resonant circuit is a series resonant circuit which is arranged in a current path which connects the UHF antenna (6) to the passive rectifier circuit (8).

8. The electronic appliance (1) as claimed in claim 7, wherein the operating mode switching apparatus (18) is operatively arranged in the current path which connects the UHF antenna (6) to the passive rectifier circuit (8) for periodically interrupting this current path.

9. The electronic appliance (1) as claimed in claim 1, wherein the modulation signal has a carrier signal which is modulated with an information signal, the detection device (16) has a demodulation device for demodulating the information signal, the detection device (16) has a correlation device for comparing the information signal with a predetermined address signal that is associated with the electronic appliance (1), and the correlation device has a control connection to the operating mode switching device (18) such that the electrical circuit is woken only when the data signal matches the address signal.

10. The electronic appliance (1) as claimed in claim 9, wherein the electrical circuit further includes a UHF transceiver (3) that is connected to the UHF antenna (6) in the form of a radio node.

11. The electronic appliance (1) as claimed in claim 10, wherein the electrical circuit further includes a microcomputer (2).

12. The electronic appliance (1) as claimed in claim 11, wherein the operating mode switching device (18) is for selectively or alternately connecting the UHF antenna (6) to the UHF transceiver (3) or the passive filter stage (7), the operating mode switching device (18) has the control connection to the detection device (16) such that the UHF antenna (6) is connected to the passive filter stage (7) in the quiescent state of the electrical circuit and to the UHF transceiver (3) in the operating state.