WO2020217219A4

WO2020217219A4 - Method of load modulation, antenna system and chip for load modulation on the side of picc device

Info

Publication number: WO2020217219A4
Application number: PCT/IB2020/053883
Authority: WO
Inventors: Milan Hammer
Original assignee: Logomotion, S.R.O.
Priority date: 2019-04-24
Filing date: 2020-04-24
Publication date: 2020-12-10
Also published as: SK289183B6; WO2020217219A1; SK500222019A3

Abstract

During communication between PICC device and PCD device the load of antenna is modulated on the side of the PICC device by means of a switch controlled by the control unit pursuant to the transferred data. The control unit either directly or indirectly, through demodulator (7), controls the switches (3, 4) themselves of at least two antennas (1, 2) with their own resonant circuits, whereby the control of the switches (3, 4) is synchronized with the identical data flow and the level of load of individual antennas (1, 2) on the side of the PICC device is different. The first antenna (1) and the second antenna (2) are mutually close in such a way that both have inductance bonding with the antenna (6) of the PCD device. The second antenna (2) is placed in parallel by the first antenna (1) or the second antenna (2) is placed perpendicularly to the first antenna (1). The second antenna (2) or multiple further antennas of PICC devices are loaded (short-circuited) in larger degree than is suitable for the first antenna (1), by which the output of the antenna (6) on the side of the PCD device is more intensively influenced.

Claims

1/4 AMENDED CLAIMS received by the International Bureau on 26 October 2020 (26.10.2020) P A T E N T C L A I M S

1. A method of a load modulation on a side of a PICC device during a communication between the PICC device and a PCD device, during which a load of an antenna on the side of the PICC device is changed by means of a switch controlled by a control unit pursuant to transferred data, and the control unit controls independent switches (3, 4) of at least two antennas (1 , 2) with their own resonant circuits, is characterized by the fact, that the control of the switches (3, 4) is synchronized with a data flow, whereby level of the load of individual antennas (1, 2) on the side of the PICC device differs from one another, and a signal from the first antenna (1) is demodulated for a retrospective acquirement of a digital data output within the PICC device and the data output is then subsequently used fir the control of the switching of the second switch (4).

2. The method of the load modulation on the side of the PICC device according to the claim 1 is characterized by the fact, that the first antenna (1) on the side of the PICC device is loaded during modulation only to such a degree that an output from the first antenna (1) provides the PICC device with a sufficient power supply and/or a basic excitation signal from the PCD device, and the second antenna (2) on the side of the PICC device is loaded in a larger degree than the first antenna (1)· 3. An antenna system for a load modulation on a side of a PICC device, which includes a first resonant circuit with a first antenna (1), which is connected to a PICC controller (5), where the first resonant circuit of the first antenna (1) is switched by a first switch

(3) which is connected to a data output from a control unit of the PICC controller (5), and the antenna system includes at least one further antenna connected in the independent resonant circuit which is switch by another switch which is connected with a data flow of the modulation of the first antenna (1), i s characterized by the fact, that it a demodulator (7) is connected between the PICC controller’s

(5) outputs and the resonant circuit of the first antenna (1), whereby the data output of the demodulator (7) is connected to the control of the second switch (4).

4. The antenna system for the load modulation on the side of the PICC device according to the claim 3 i s characterized by the fact, that another switch is connected with the data output from the control unit of the PICC controller (5).

5. The antenna system for the load modulation on the side of the PICC device according to the claim 3 or 4 i s characterized by the fact, that it includes a second antenna (2) connected in an independent second resonant circuit which is switched by a second switch (4), whereby the second switch (4) is connected with the data output from the control unit of the PICC controller (5).

6. The antenna system for the load modulation on the side of the PICC device according to the claim 5 i s characterized by the fact, that the first antenna (1) and the second antenna (2) are placed in a mutual vicinity in such a way that both have an induction bonding with an antenna

(6) of the PCD device.

7. The antenna system for the load modulation on the side of the PICC device according to the claim 5 or 6 is characterized by the fact, that the first antenna (1) and the second antenna (2) are formed by solenoid windings on an air or ferrite core.

8. The antenna system for the load modulation on the side of the PICC device according to any of the claims 3 to 7 is characterized by the fact, that an inductance of the solenoid windings ranges from 750nH to 2mH and a quality Q ranges from 15 to 50.

9. The antenna system for the load modulation on the side of the PICC device according to any of the claims 3to8 is characterized by the fact, that the first antenna (1) and the second antenna (2) are constructionally identical elements.

10. The antenna system for the load modulation on the side of the PICC device according to any of the claims 3to9is characterized by the fact, that the second antenna (2) is placed in parallel by the first antenna (1).

11. The antenna system for the load modulation on the side of the PICC device according to the claim 10 i s characterized by the fact, that a gap between the first antenna (1) and the second antenna (2) is less than five times a width of the first antenna (1) or the width of the second antenna (2); preferably the gap is less than 5 mm.

12. The antenna system for the load modulation on the side of the PICC device according to any of the claims 3to9is characterized by the fact, that the second antenna (2) is placed perpendicularly on the first antenna (1), preferably arranged into a shape of letter L or letter T.

13. The antenna system for the load modulation on the side of the

PICC device according to any of the claims 3 to 12 is characterized by the fact, that the second switch (4) includes two MOS FET transistors.

14. A chip for the load modulation on the side of the PICC device, where the load modulation is realized by the method according to the claim 1 or2 is characterized by the fact, that it includes at least two integrated switches of the load for at least two independent resonant 4/4

antenna circuits, whereby it has a respective number of pairs of outputs for a connection of the resonant antenna circuits.

STATEMENT UNDER ARTICLE 19 (1 )

A feature from the original claim 3, which according to written opinion of the ISA includes novelty as well as inventive step, has been moved into the first claim. At the same time, we do not agree, that document D1 is an obstacle to the inventive step. Document D1 uses multiple antennas to achieve sufficient power transmission for powering the passive transponder, but it does not use load modulation according to claim 1, wherein the level of the load of individual antennas on the side of the PICC device differs from one another. Although document D1 has a similar looking circuit diagram of multiple antennas, but a different procedure is perfmormed by this circuit.

The original claim 3 has lapsed after merging with the first claim. New claim 3 was created by combining the original claim 4 and 14. Connection with the demodulator is not only new but also inventive compared to the document Dl, since document D1 does not deal with demodulation at all and it solves a different technical problem. In our invention, we strive for a significant improvement in the response amplitude (LMA - load modulation amplitude) on the side of the PCD device. Document Dl solves the problem of how to support generating a supply voltage for a passive transponder.

From the wording of the original claim 4, which was added at the end of the claim by a conjunction "preferable", we have created a new dependent claim with the number 4. Other amendments of the claims are only of a formal nature consisting mainly in renumbering.

With regard to the conclusions of written opinion of the ISA, where inventive step was granted to claims 3 and 14, we consider that after the submitted changes all independent claims 1 and 3 and also dependent claims 2, 4 to 13 meet the criteria of novelty and inventive step.

We consider claim 14 (before as claim 15) also to be inventive. Document Dl in no way guides to integrate the switches in an integrated circuit. A person skilled in the art would not use an integration to a chip with knowledge of Dl, but he would increase the level of transmission energy or he would increase the size of the receiving antennas. Document Dl does not address the limitations of the small available space, the transponder according Dl is in the remote control, which has relatively large dimensions compared to the chip level. The integration of the switch does not seem obvious, on contrary, at first glance it seems to be an inappropriate solution. The advantage is that a more reliable communication is achieved on larger distance already with small, miniature dimensions of the antenna on the side of the PICC device. It should also be noted that if such a chip was to be considered as common, it would already be on the market, as the range of chips is very wide, even for the connections that are less unlikely.