Abstract: An over-voltage protection circuit (i.e., a limiter), includes: a first switching block having a plurality of semiconductor elements, serially connected to each other and turned on in sequence according to the magnitude of an input voltage; and a plurality of second switching blocks, in which each of the second switching blocks includes a pair of serially connected semiconductor elements having different current properties. The second switching blocks are connected in parallel to the first switching block. By minimizing a leakage current when an input voltage is below a reference voltage and by maximizing a leakage current when the input voltage is above the reference voltage, the limiter prevents excessive current from flowing into the RF tag circuit when the input voltage is below the reference voltage, and ensures that a sufficient amount of current is supplied to a regulator when the input voltage is below the reference voltage.

Abstract: An integrated circuit structure in which a plurality of Schottky diodes and a capacitor are integrally formed. The integrated circuit structure includes a substrate including an N-type semiconductor doped with N-type impurities and a P-type semiconductor doped with P-type impurities; a first conductive layer laminated on the substrate so that the first conductive layer is electrically connected to the N-type semiconductor and the P-type semiconductor; a dielectric layer laminated on an upper surface of the first conductive layer; and a second conductive layer laminated on an upper surface of the dielectric layer so that the second conductive layer forms a capacitor together with the first conductive layer and the dielectric layer. Accordingly, when the integrated circuit structure is used in a rectification circuit, the size of an entire circuit can be reduced.

Abstract: A mobile terminal communicates with a base station to request channel allocation for RFID communication, receives a channel from the base station, and communicates with an RFID tag through the allocated channel.

Abstract: A method and apparatus for managing metadata in a portable terminal are provided. The method includes, upon insertion of an external memory, acquiring a unique identifier of an external memory, determining whether a record having information identical to information of a file included in the external memory exists if the unique identifier is identical to a previously stored unique identifier, and reusing metadata included in the record if the record exists.

Abstract: A level shifter increase a voltage level of an output signal with relatively lower power consumption by adopting current-starved configuration. The level shifter includes an input unit and a driving unit. The input unit includes a current-starved inverter configured to generate a control signal in response to an input signal and a bias voltage. The input unit is powered by a first power supply voltage. The driving unit generates an output signal in response to the control signal. The output signal has a voltage level higher than the input signal, and the driving unit is powered by a second power supply voltage higher than the first power supply voltage.

Abstract: Disclosed are a temperature measurement apparatus and method for measuring temperature by using RF signals having different frequencies. The temperature measurement apparatus includes a parameter generation unit for generating a first parameter based on a radio frequency (RF) signal having a first frequency and a second parameter based on an RF signal having a second frequency; a parameter detection unit for detecting the generated first and second parameters; and a control unit for calculating a temperature value based on the detected first and second parameters. Accordingly, the temperature measurement apparatus can measure temperature by use of existing components and received RF signals without any addition of a temperature sensor, as well as measure temperature precisely without having any influence on the intensities of RF signals that can vary due to the changes of transmission distances and signal-receiving environments.

Abstract: A radio frequency identification (RFID) reader includes a transmitter generating a transmission signal for transmission to a tag, a receiver receiving a response signal from the tag, a leakage compensator compensating a leakage signal leaked from the transmitter to the receiver in response to a leakage control signal, and a control unit performing a leakage test operation by applying a test signal to the transmitter, and calculating and storing a leakage parameter for generating the leakage control signal using a level difference of the test signal and a level difference of a test leakage signal leaked to the receiver.

Abstract: A Radio Frequency (RF) transmission method of a Radio Frequency Identification (RFID) reader using a plurality of channels is provided. The method includes: selecting at least part of the plurality of channels, measuring an RF power of each of the selected channels, determining a transmission environment of the RF according to a measurement determination, and modulating an RF signal according to the determined transmission environment.

Abstract: A limiter for controlling an overvoltage and an RFID tag having the same are provided. The limiter includes a first limiter part and a second limiter part serially connected to the first limiter part. The second limiter part has at least one limit diode whose threshold voltage is lower than that of elements in the first limiter part. Accordingly, if an overvoltage is input, the limiter can maximize the input current drop so that the limiter can maximize the leakage voltage. As a result, the RFID tag can prevent the RFID driving part from being damaged due to the overvoltage. In addition, the RFID tag can normally operate regardless of the intensity of the driving voltage input from the RFID reader, so that the yields of products can improve.

Abstract: A radio frequency identification (RFID) recorder for cancelling a leakage signal includes a digital unit calculating and storing an amplitude and a phase of the leakage signal, and a leakage cancellation circuit generating a leakage cancellation signal to cancel the leakage signal in response to a control of the digital unit.

Abstract: A method and apparatus for preventing illegal reuse of Digital Right Management (DRM) content in a portable terminal is provided. The method includes performing user authentication when there is an attempt to restore a Right Object (RO) backup file, and identifying information on the RO backup file to be pre-restored in a terminal, and determining if the RO backup file can be restored according to the identified information.

Abstract: A low leakage Schottky diode and fabrication method thereof. The Schottky diode includes a n-type semiconductor; an anode having a circular periphery formed in a region above the n-type semiconductor; and a cathode formed in a region above the n-type semiconductor and having a pattern surrounding and set apart from the outer periphery of the anode. Because there are no edges at the anode and cathode interface, leakage current is minimized.

Abstract: Provided are an apparatus and a method for saving a memory in a portable terminal, the method includes receiving a request for basic data and an address indicating a storage position of the basic data; determining whether the requested basic data has been stored in a paging buffer; if it is determined that the requested basic data has not been stored in the paging buffer, transforming the address of the requested basic data into an address of a corresponding compressed block using a block address table; searching the compressed basic data for the compressed block corresponding to the address of the compressed block; decompressing the searched compressed block; storing data of the decompressed block in the paging buffer; and returning the requested basic data stored in the paging buffer.

Abstract: An integrated circuit structure in which a plurality of Schottky diodes and a capacitor are integrally formed. The integrated circuit structure includes a substrate including an N-type semiconductor doped with N-type impurities and a P-type semiconductor doped with P-type impurities; a first conductive layer laminated on the substrate so that the first conductive layer is electrically connected to the N-type semiconductor and the P-type semiconductor; a dielectric layer laminated on an upper surface of the first conductive layer; and a second conductive layer laminated on an upper surface of the dielectric layer so that the second conductive layer forms a capacitor together with the first conductive layer and the dielectric layer. Accordingly, when the integrated circuit structure is used in a rectification circuit, the size of an entire circuit can be reduced.

Abstract: A planar small antenna and a small strip radiator are provided which have increased bandwidth. The small strip radiator has a main strip pattern and a plurality of convoluted strip patterns terminating the main strip pattern at each end. The plurality of convoluted strip patterns are arranged in mirror-symmetrical arrangement with reference to the longitudinal axis of the main strip such that one pair of convoluted strip patterns is convoluted clockwise while another pair is convoluted counterclockwise. As a result, an electrically small antenna radiator requires less metal or conductive material than conventional radiators, and also can operate without adversely affecting the radiation characteristics of the antenna.

Abstract: A radio frequency identification (RFID) barcode includes a plurality of sets of conductive strips and a plurality of inductors, wherein each of the plurality of sets of conductive strips respectively includes a plurality of conductive strips separated by at least one gap, and each of the plurality of inductors is disposed in the at least one gap of a corresponding set of conductive strips and connects two of the plurality of conductive strips of the corresponding set of conductive strips. The sets of conductive strips are arranged in parallel and separated from one another in a predetermined distance. The RFID barcode may further include a dielectric substrate supporting the sets of conductive strips and the inductors, and a metal layer provided on all of a rear surface of the dielectric substrate.

Abstract: An oscillator tuning system and an oscillator tuning method are provided. The system includes a determination unit which determines whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and a frequency tuner which tunes a driving frequency of the RFID oscillator according to a result of the determination. The method includes determining whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and tuning a driving frequency of the RFID oscillator according to a result of the determination.

Abstract: Disclosed is a rectifier for supplying double voltage and an RFID tag thereof. The rectifier includes a charging part for charging an input voltage induced to input ends by a received radio frequency (RF) signal; a power provider for charging a sum voltage corresponding to the sum of the input voltage induced to the input end and the voltage charged in the charging part as a power voltage, and discharging the charged power voltage to provide a direct current (DC) power; and a switching part for switching to supply the input voltage induced at the input ends to the charging part during a first interval and switching to supply the sum voltage to the power provider during a second interval. Accordingly, double voltage can be supplied to other electric elements formed in the RFID tag and overcurrent caused by overvoltage can be prevented from flowing into the elements.

Abstract: An integrated circuit structure in which a plurality of Schottky diodes and a capacitor are integrally formed. The integrated circuit structure includes a substrate including an N-type semiconductor doped with N-type impurities and a P-type semiconductor doped with P-type impurities; a first conductive layer laminated on the substrate so that the first conductive layer is electrically connected to the N-type semiconductor and the P-type semiconductor; a dielectric layer laminated on an upper surface of the first conductive layer; and a second conductive layer laminated on an upper surface of the dielectric layer so that the second conductive layer forms a capacitor together with the first conductive layer and the dielectric layer. Accordingly, when the integrated circuit structure is used in a rectification circuit, the size of an entire circuit can be reduced.

Abstract: An apparatus and method for dynamically changing a password are provided. In the method, a random number is generated, and an original password and an operator are checked. The original password is changed by performing an operation of the random number and the original password based on the operator. Accordingly, the password exposure can be prevented and the personal information and asset information can be protected without using additional devices.