Other

Ams R&d D.o.o.

Ams International Ag

Ams Ag

Ids Microchip Ag

Ams R&d Analogni Polprevodniki, D.o.o.

Kunc, Vinko

Vodopivec, Andrej

Atanasijevic-kunc, Maja

Stern, Anton

Andrej Vodopivec

Vinko Kunc

Kosta Kovacic

Maja Atanasijevic-Kunc

Anton Pletersek

Anton Stern

William Peyton Roberts

Maksimilijan Stiglic

Oluf Alminde

A controlled switching circuit (csc) comprises two controlled switches (cs, cs) fabricated with PINTOS transistors and connected between its output terminal as well as a battery (b) or a rectifier rectifying voltage induced in an antenna. Conditions of the battery voltage and the rectified voltage with a time delay are checked. Only when the battery voltage gets unacceptable and the value of rectified voltage exceeded a preset value tag circuits are supplied by the rectified voltage induced in an antenna. The invention provides for an automatic selection of a way of supplying an RFID tag in a way that it is stably supplied by a battery as far as still possible, but just according to the invention this is rendered possible for a longer time due to a very low voltage drop across a controlled switching circuit, and that a supply by a radio-frequency radiation field is selected only when the battery gets depleted.

Method for a battery and passive power supply to an RFID tag and a switching circuit for carrying out said method

A sensor-front-end processor (SFEP) predrives external sensors during a predominant part of time. In a low-consumption state it waits to receive a command (sc; st) to acquire and condition sensor signals. After receiving the command it drives the sensors, sets its own measuring range, acquires a coarse code (ccc, vcc) of a current and voltage sensor signal, conditions said signal and acquires a signal fine code (ccf, vcf). The command (sc) is generated in adjustable time intervals. The sensor-front-end processor acquires and conditions the signals from the sensors consecutively one after another. The command (st) is generated whenever a request (irq) to interrupt predriving one of the sensors was generated, i.e. whenever a level of the sensor signal or its relative change with respect to the previous measurement drops out from an interval for this sensor. The detected codes are stored in the memory.

RFID label comprising an interface to external sensors

A method of communication of an active smart RFID label with a user interrogator and a professional interrogator, said professional interrogator enabling a service provider to fully control said active smart RFID label and by means of which interrogator a content and a form of an extract of data, which are collected by a sensor, which is comprised of in the label, as well as a location within the label as location of said extract of data being collected by said label sensor, said location being accessible by the user interrogator are determined. A service user gets concisely acquainted with the service provided by the label by means of a widely used interrogator, whereat he cannot influence the data contained in the label or even its functioning neither needs any additional knowledge to communicate with said label.

Method of communication of an active smart RFID label with a user interrogator and a professional interrogator

A memory access arbiter (MAA) in an RFID tag is connected to an unique address space (UAS), which comprises a non-volatile memory (NVM), a transferred data memory (TDM) and a status-information memory (SIM) storing information on the status of the transferred data memory (TDM). The transferred data memory (TDM) and the status-information memory (SIM) are volatile memories, e.g. of the RAM type having a memory capacity of 16 bits or 32 bits according to the standard of an applied RFID communication. The RFID tag of the invention provides for a faster communication between an interrogator and an external logic element by one order of magnitude, which is due to fast volatile memories for transferred data as well as for corresponding status information. A still higher communication rate is achieved by introducing a command that has not yet been standardized.

RFID tag with an improved communication between an external logic element conductively connected thereto and an interrogator as well as a method for such communication

A calibrating output signal of the transmitter is generated in an interrogator in that a first output signal of a local oscillator is shallowly amplitude-modulated with a pilot signal having a frequency at which a contactless-card encodes data. A receiver reference signal is generated by combining the calibrating output signal of the transmitter and a signal whose carrier signal has a frequency equaling the frequency of the local oscillator signals, conducting the combined signal through a band-pass filter and amplifying it. A first and a second receiver output signals are cleared by subtracting the receiver reference signal, which has been attenuated by a calibrated factor and has a calibrated polarity, from the first and the second receiver output signal, respectively. The attenuation factor and the polarity of the receiver reference signal are sporadically calibrated for each of both receiver output signals by determining and setting the attenuation factor and the polarity of the receiver reference signal as a pair of values for each of both receiver output signals, at which pair of values the first and the second cleared receiver output signals have the lowest amplitude. The signal-to-noise ratio for the interrogator receiver output signal is improved, because this signal no longer contains an amplitude noise of the interrogator transmitter.

Method for reducing a noise in a signal received in a contactless-card interrogator and a circuit to perform said method

Prior to logging of a process flags for locking at all addresses of a logging area of a tag are set to state 1 by means of an interrogator. A high limit (h) and a low limit (l) of an interval (l-h) of such values (v) of a physical parameter are determined, which are proper for preserving usability of a tagged article. Said values (v) acquired with a sensor and acquisition times related thereto are converted into less numerous data characterizing the process by observing said limits (h, l). Said data characterizing the process are logged in said logging area. Said process log cannot be modified in any way at a later stage. The invention also provides for an efficient observation of longer period of the process in the tagged article in order to inspect the usability thereof.

Method for a secure non-volatile logging in an active RFID tag of a process in a tagged article

When communicating with a traditional interrogator of passive smart tags, an actively transmitting smart tag of the invention, even within a data frame being transmitted, observes a first phase (&#x3a6;i) being a phase of a voltage induced in a tag's antenna by an interrogator's high-frequency carrier signal and transmits wave packets in that it excites the antenna with a voltage having a phase (&#x3a6;t), which is always set at the beginning of transmission of each said wave packet shifted with respect to said first phase (&#x3a6;i) by the same phase angle (&#x394;&#x3a6;). At &#x394;&#x3a6;=180&#xb0; an amplitude of voltage across an interrogator's antenna, when some of said wave packets influence this antenna, attains the largest attainable interference rise. Miniature actively transmitting smart tags are enabled to wirelessly communicate with said traditional interrogator and a communication range of pocket-sized tags is herewith increased.

Method and circuit intended for high-frequency communication between an interrogator and a smart tag

Output terminals (o, o) of a differentially excited transmitting circuit (TC) are connected through matching capacitors (MC, MC) to connecting terminals of the oscillatory circuit antenna (OCA) on the other side said connection terminals are directly connected to input terminals of a receiving circuit (RC). Each of the input terminals (i, i) of the receiving circuit (RC) is connected to an earthing terminal (m) of the integrated transceiver circuit (TRC) through a corresponding undervoltage-protection diode (UPD, UPD) determining a lower potential value of a received signal and a corresponding overvoltage-protection diode (OPD, OPD) determining an allowed upper potential value of the received signal exceeding said lower potential value by the highest possible voltage still allowable by the integrated transceiver circuit (TRC). The highest allowable voltage amplitude of the received signals supplied to the input of the receiving circuit (RC) practically equals the highest possible voltage, which is still allowed by the integrated receiver circuit, thus exceeds energization voltage.

Method and circuit for transmitting and receiving radio waves with a single oscillatory circuit antenna

A difference between an output current signal (mos) of the mixing circuit (MC) and a current from a controlled current source (CCS) is conducted to an input of an operational amplifier (A). A control voltage (cv) for said current source is a voltage at the output of the operational amplifier (A) being filtered by a low-pass filter, whose limiting frequency equals a low frequency limit of the modulation signal in the received signal (rs). The method is speeded up in that the limiting frequency of the low-pass filter is increased by two to three orders of magnitude at the beginning and is gradually lowered to said value. A rather short time duration of the transient process is achieved so that the working point with a low voltage of the DC component and low-frequency components is set at least five times faster than so far.

Method and circuit for a fast reduction in voltage of a DC component and low-frequency components at a mixing circuit output in a receiver of a UHF transceiver

According to the method for regulating the supply voltage of an electronic circuit a regulating element with variable resistivity and the outer supply voltage being applied to an input terminal of said regulating element is controlled by an amplified difference between a reference voltage and a part of a regulated supply voltage whereat at first an instant, on which the regulating circuit and the electronic circuit start operating, is detected, and then such value of the reference voltage is set on said instant that the regulated supply voltage will equal a maximum allowable supply voltage of the electronic circuit and the supplied electronic circuit puts itself in a state of a maximum current consumption. Then an operating voltage drop across said regulating element is measured at regular time intervals and the reference voltage is then each time reduced by one degree until said operating voltage drop is below or equals a chosen most appropriate value of said operating voltage drop. The supplied electronic circuit puts itself in a state of a normal current consumption when said operating voltage drop has exceeded the chosen most appropriate value of said voltage drop. According to a variant embodiment the operating voltage drop is then uninterruptedly measured and, if its value decreases below a chosen minimum value of said operating voltage drop due to a disturbance in the outer supply voltage, a flag is set in a memory in the case of a disturbance potentially dangerous to the electronic circuit.

Method for regulating supply voltage

The measurement of a very low intensity of an electric current is carried out by 5 integrating the electric current over integration cycles having a time period ti and measuring a peak value of a sawtooth voltage at an integrated circuit output each time at the end of the integration cycle, whereat noise voltage components of a frequency above a cut-off frequency, which has a value of the order of magnitude (0,1&#xd7;2&#x3c0;&#xd7;ti), being parts of a voltage of a noise generated in an operational amplifier comprised in the integrated circuit are filtered out of the said sawtooth voltage and noise components, which have the origin in the high-frequency voltage components of Johnson noise, which appear in the low-frequency spectral part of the sawtooth voltage as aliasing, are subtracted from a filtered sawtooth voltage. A higher absolute accuracy of the measurement is achieved by means of a reduction of the direct as well as the aliasing contribution of the Johnson noise of the operational amplifier in the measuring circuit.

Method and circuit for reducing noise when measuring intensity of electric current

A voltage comparator where the difference of currents from transistors is converted into voltage, which is amplified and conducted to a gate terminal of a switching transistor. A source of a limiting transistor is connected to the gate terminal. The voltage at the gate terminal when the switching transistor is quiescent is equal to a value between eight and nine tenths of the switching voltage at the gate of the transistor, at which voltage the transistor triggers a switching in the output stage. A response to an input voltage change at one direction of the sign reversal of the difference of the input voltages is fast. The voltage comparator is robust and reliable with regard to temperature variations.

Voltage comparator

A transmission of a signal through an isolation interface with a capacitive barrier is performed so that in an input circuit of the interface by integrating with an appropriate time constant the slope rates of the edges of signal replicas U of the transmitted input signal Ui are adjusted and that the said signal replicas are differentiated either in an appropriate differentiating unit, whereat the time constants of these differentiating units are shorter than the rising and falling-off times of the signal replicas and are advantageously in the order of magnitude of 1 nanosecond or below. Therefore, in a circuit on the output side of the capacitive barrier no amplifier in front of voltage comparators is needed, which makes it possible that the pulse width is maintained extremely precisely. The data transmission is immune from the fast variation in the order of magnitude of 10 kV/&mgr;s of the potential difference between the voltage supplying sources for the input and the output circuits. By the invention a digital data transmission up to the frequency of 100 MHz is rendered possible.

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Ljubljana, Slovenia

Andrej Vodopivec