RADIO-FREQUENCY IDENTIFICATION READER DEVICE

• US 20150371065A1
• Filed: 11/10/2014
• Published: 12/24/2015
• Est. Priority Date: 06/23/2014
• Status: Active Grant

• Current Assignee: Wistron NeWeb Corporation (Wistron Corporation)
• Original Assignee: Wistron NeWeb Corporation (Wistron Corporation)
• Inventors: Chang, Chung-Ping, Liu, Chia-Chang
• Granted Patent: US 9,378,400 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06K 7/10009 sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching

Abstract

A radio-frequency identification reader device including a plurality of antennas, a switch module, a coaxial cable, and a reader is provided. The switch module is electrically connected to the antennas. The coaxial cable is electrically connected to the switch module. The reader transmits a DC voltage, a control signal, and a radio-frequency signal to the switch module through the coaxial cable. The switch module generates an operation voltage by the DC voltage and the control signal. The switch module selects one of the antennas as a preset antenna by the control signal and drives the preset antenna by the radio-frequency signal.

Claims

1. A radio-frequency identification reader device, comprising:

a plurality of antennas;

a switch module electrically connected to the antennas;

a coaxial cable electrically connected to the switch module; and

a reader transmitting a direct current voltage, a control signal, and a radio-frequency signal to the switch module through the coaxial cable, wherein the switch module generates an operation voltage by the direct current voltage and the control signal, and the switch module selects one of the antennas as a preset antenna by the control signal and drives the preset antenna by the radio-frequency signal.

2. The radio-frequency identification reader device of claim 1, wherein the coaxial cable comprises an inner conductor and an outer conductor, and the outer conductor is electrically connected to a ground terminal.

3. The radio-frequency identification reader device of claim 2, wherein the reader comprises:

a signal generating circuit generating the direct current voltage and the control signal;

a high-frequency blocking element electrically connected to the signal generating circuit and the inner conductor, wherein the high-frequency blocking element transmits the direct current voltage and the control signal and blocks the radio-frequency signal; and

a low-frequency blocking element electrically connected to the inner conductor, wherein the low-frequency blocking element transmits the radio-frequency signal and blocks the direct current voltage and the control signal.

4. The radio-frequency identification reader device of claim 3, wherein the high-frequency blocking element is an inductor and the low-frequency blocking element is a capacitor.

5. The radio-frequency identification reader device of claim 3, wherein the signal generating circuit comprises a switch, the switch receives a power voltage, the switch is turned on and continuously outputs the power voltage as the direct current voltage in a first period, and in a second period, the signal generating circuit switches a state of the switch such that the switch outputs a plurality of pulses configured to foil the control signal.

6. The radio-frequency identification reader device of claim 3, wherein the signal generating circuit comprises a buffer, the signal generating circuit outputs the direct current voltage through the buffer in a first period, and the signal generating circuit outputs the control signal through the buffer in a second period.

7. The radio-frequency identification reader device of claim 2, wherein the switch module comprises:

a high-frequency blocking element electrically connected to the inner conductor, wherein the high-frequency blocking element transmits the direct current voltage and the control signal and blocks the radio-frequency signal;

a low-frequency blocking element electrically connected to the inner conductor, wherein the low-frequency blocking element transmits the radio-frequency signal and blocks the direct current voltage and the control signal;

a converting circuit converting the direct current voltage and the control signal from the high-frequency blocking element into the operation voltage; and

a switching circuit operated at the operation voltage, wherein the switching circuit generates a plurality of digital signals according to the control signal from the high-frequency blocking element, and transmits the radio-frequency signal from the low-frequency blocking element to the preset antenna according to the digital signals.

8. The radio-frequency identification reader device of claim 7, wherein the high-frequency blocking element is an inductor and the low-frequency blocking element is a capacitor.

9. The radio-frequency identification reader device of claim 7, wherein the converting circuit comprises:

a diode, wherein an anode of the diode is electrically connected to the high-frequency blocking element and a cathode of the diode outputs the operation voltage; and

a capacitor, wherein a first terminal of the capacitor is electrically connected to the cathode of the diode and a second terminal of the capacitor is electrically connected to the ground terminal.

10. The radio-frequency identification reader device of claim 7, wherein the converting circuit comprises:

an inductor, wherein a first terminal of the inductor is electrically connected to the high-frequency blocking element and a second terminal of the inductor outputs the operation voltage; and

a capacitor, wherein a first terminal of the capacitor is electrically connected to the second terminal of the inductor and a second terminal of the capacitor is electrically connected to the ground terminal.

11. The radio-frequency identification reader device of claim 7, wherein the switching circuit comprises:

a controller electrically connected to the high-frequency blocking element and operated at the operation voltage, wherein the controller generates the digital signals according to the control signal; and

a radio-frequency switch electrically connected to the controller and the low-frequency blocking element and transmitting the radio-frequency signal to the preset antenna according to the digital signals.