RU73763U1 - READER CONTACTLESS RADIO FREQUENCY - Google Patents

Abstract

The utility model is intended for use in contactless radio frequency identification systems in the standards I-CODE, ISO 15693 and ЕРС and can be used in systems for monitoring the movement of goods, access restrictions, as well as in other systems that require the use of contactless RF tags and require their reading on ranges of more than 1 meter.

To implement data processing, a specialized IC is used f. Philips CLRC632 in non-standard inclusion. This IC is designed to work in readers of short range (up to 0.1 m) and contains a controller for processing communication protocols, a modulator and demodulator of RF signals. The chip is designed to work with small signals that allow you to work with a wireless tag at a distance of up to 10 cm.

This IC during transmission is used as a generator of the reference modulated signal. The RF signal generated by the IC is fed to an external power amplifier. The amplifier allows you to amplify the output signal of the chip (about 250 mW) to the power required for the reader to work with wireless tags at a distance of up to 1.5 m (8 W).

The received signal is fed to an external antenna designed for communication with wireless tags.

Being in the radiation field of the reader’s antenna, the emf is induced at the tag’s antenna, from which the tag’s power is supplied. The transfer of commands to the label is carried out due to the amplitude modulation of the carrier signal. Having received the data, the label decodes them, and gives an amplitude-modulated response to the reader. The received data is demodulated and fed to the CLRC632 for decoding.

In receive mode, the microcircuit is designed to work with small signals (amplitude less than 1 V) coming from a small radius antenna

at rated output power. To ensure the indicated values of the input signal and high sensitivity, an external demodulator is required. The signal from the antenna receives a circuit that provides demodulation of the incoming AM signal. At the output of the demodulator, a signal is formed corresponding to the shape of the envelope of the original signal. The demodulated and amplified signal is fed to the AM modulator. The signal at the output of the modulator is equivalent to the original one coming from the antenna, but has a greater modulation depth, as well as a smaller amplitude of the carrier signal. This signal is fed to the input of the IC for decoding.

Thanks to this solution, the processor module is simplified and there is no need for software implementation of the data exchange protocol between the card and the reader, which greatly simplifies the product and makes the control program more reliable.

Description

The long-range reader is intended for use in systems using contactless tags of I-CODE, ISO 15693 and EPC standards. They can be used in systems for controlling the movement of goods, restricting access, as well as in other systems requiring the use of contactless RF tags and requiring their reading at ranges of more than 1 m.

The main analogues of this reader are the following products:

- RISTU6500 (Texas Instruments) (1)

- R90 (HID Corporation) (2)

- LRP2000 (Belgravium) (3)

These readers are similar in characteristics, provide operation in the frequency range of 13.56 MHz. The reader (1) provides operation in ISO 15693 standards, and is also compatible with Tag-IT tags manufactured by Texas Instruments. The disadvantages of this reader include the inability to work in the standard I-CODE and EPC, as well as high power consumption (24 V, 48 W).

The reader (2) is structurally made together with the antenna, and has a relatively low reading distance for readers of this level - up to 0.5 m.

The reader (3) is compatible with marks of ISO 15693 standards, and provides work with tags at a distance of up to 1 m.

The closest analogue is the reader SLRM900 (Philips). This reader provides work in the specified standards. The reader has an output power of up to 8 watts. This reader provides the ability to read proximity tags at distances

up to 1.3 m. The disadvantage of the reader is high power consumption (more than 30 watts).

During development, the main task was to reduce energy consumption, simplify and reduce the cost of reader design through the use of modern element base.

A long-range non-contact radio-frequency reader comprising a reader module, an antenna, a power source, the reader module including a central processor, an external interface module, a radio data processing module, a power amplifier, a receive signal demodulator, characterized in that an IC-based radio data processing module is inserted therein CLRC632 and an additional modulator of AM signal, and the output of the microcircuit on which the output RF signal is generated is not supplied to the antenna, to the power amplifier, to ensure ovnya signal power required for the contactless label at distances up to 1.5 m, and the signal on the receive path input of the IC is supplied from an external signal AM demodulator, which ensures the required sensitivity.

The contactless radio frequency reader is a complex consisting of (see figure 1):

- reader module (1);

- antennas (2);

- power source (3).

The reader module consists of:

- central processor (4);

- module of external interfaces (5);

- a radio data processing module (6);

- RF power amplifier (7);

- AM demodulator (8);

- AM modulator (9).

The processor module (4) provides control of the reader, receiving commands from the external interface module (5), as well as issuing the received data.

To implement data processing (6), a specialized IC is used f. Philips CLRC632 in non-standard inclusion. This IC is designed to work in readers of short range (up to 0.1 m) and contains a controller for processing communication protocols, a modulator and demodulator of RF signals. The chip is designed to work with small signals that allow you to work with a wireless tag at a distance of up to 10 cm.

This IC during transmission is used as a generator of the reference modulated signal. The RF signal generated by the IC is fed to an external power amplifier (7). The amplifier allows you to amplify the output signal of the chip (about 250 mW) to the power required for the reader to work with wireless tags at a distance of up to 1.5 m (8 W).

The received signal is fed to an external antenna (2), designed for communication with wireless tags.

Being in the radiation field of the reader’s antenna, the emf is induced at the tag’s antenna, from which the tag’s power is supplied. The transfer of commands to the label is carried out due to the amplitude modulation of the carrier signal. Having received the data, the label decodes them, and gives an amplitude-modulated response to the reader. The received data is demodulated and fed to the CLRC632 for decoding.

In the receiving mode, the microcircuit is designed to work with small signals (with an amplitude of less than 1 V) coming from a small radius antenna at a rated output power. To ensure the indicated values of the input signal and high sensitivity, an external demodulator is required. The signal from the antenna receives a circuit that provides demodulation of the incoming AM signal (8). The demodulated and amplified signal is fed to the AM modulator (9). On

the second input of the modulator receives a reference signal of 13.56 MHz generated by CLRC632. At the output of the modulator, an AM signal is generated corresponding to the requirements of the IC. This signal is equivalent to the original one coming from the antenna, but has a greater modulation depth, as well as a smaller amplitude of the carrier signal.

The output amplifier can be performed according to any scheme providing the required output power at an input signal level of 0.25 watts. To ensure suppression of harmonic components, the amplifier must contain an output low-pass filter. To reduce the power consumption of the complex, the amplifier can be performed directly on the antenna, thus increasing the efficiency of the amplifier due to the lack of the need to provide an output impedance of 50 Ohms when working on a cable.

The detector of the receiving path can be made based on a diode detector. Next, the envelope signal is filtered and amplified. The modulator can be performed according to any scheme providing amplitude modulation of the signals of the required frequency range.

Thanks to this solution, unlike the indicated analogues, the processor module is simplified and there is no need for software implementation of the data exchange protocol between the card and the reader, which greatly simplifies the product and makes the control program more reliable.

Information sources:

(1) http://www.ti.com/rfid/shtml/prod-readers.shtml

(2) http://www.hidcorp.com/russian/prod_detail.php?prod_id=74

(3) http://www.belgravium.com/product_rfid_lrp2000.asp (prototype) http://www.nxp.com/acrobat/datasheets/SLRM900_2.pdf

Claims (1)

A long-range non-contact radio-frequency reader comprising a reader module, an antenna, a power source, the reader module including a central processor, an external interface module, a radio data processing module, a power amplifier, a receive signal demodulator, characterized in that an IC-based radio data processing module is inserted therein CLRC632 and an additional modulator of the AM signal, and the output of the microcircuit on which the output RF signal is generated is supplied not to the antenna, to the power amplifier, to ensure ovnya signal power required for the contactless label at distances up to 1.5 m, and the signal on the receive path input of the IC is supplied from an external signal AM demodulator, which ensures the required sensitivity.