Abstract: A technique for simultaneously acquiring vehicle identification information and speed information of an RFID tag-attached vehicle by calculating the vehicle speed by using a Doppler shift value extracted from transmission and reception signals between the RFID tag and the RFID reader is disclosed. A method for measuring a vehicle speed by using an RFID reader installed right up on the road or at the roadside includes: transmitting a continuous wave; receiving a reflected wave with respect to the continuous wave from an RFID tag attached to a vehicle which has received the continuous wave; extracting a Doppler shift value from the continuous wave and the reflected wave; and calculating the speed of the vehicle by using the Doppler shift value.

Abstract: A low power consuming mixed mode power amplifier which includes: a low output amplifier circuit generating a power amplified result having high efficiency in a low output mode that is most frequently used; a high output amplifier circuit generating an amplified result having high linearity in a high output mode of a region consuming the most power; and an amplifier controller selectively activating the low and high output amplifier circuits according to a power level of an input signal. The high and low output amplifier circuits have a predetermined gain difference.

Abstract: Provided is a voltage controlled oscillator to which a switching bias technique is applied so as to lower flicker noise of a bias circuit and enhance phase noise characteristics, thereby reducing the overall chip area to make it possible to achieve integration. A common mode voltage applied to the bias circuit is negatively fed back to an oscillation waveform. Therefore, it is possible to stabilize the magnitude of the oscillation waveform of the voltage controlled oscillator with respect to a change in an external condition.

Abstract: An a Radio Frequency Identification (RFID) system using human body communication includes a first electrode pad receiving a signal of a reader transmitted through a human body, or outputting an output signal to the human body, a rectifier rectifying the signal of the reader to generate a direct current (DC) voltage, a power manager changing the DC voltage into an operation voltage, a modulator/demodulator demodulating the signal of the reader, or modulating the output signal of the tag to transfer the modulated signal to the first electrode pad, a digital controller performing a read or write operation in response to the signal of the reader demodulated by the modulator/demodulator, and a memory storing identification information of the tag and information according to an operation result of the digital controller.

Abstract: Provided is a direct-conversion frequency mixer for down converting a radio frequency (RF) signal into a baseband signal, in which a single phase RF signal and a quadrature location oscillation (quadrature LO) signal are used to generate the baseband signal, the frequency mixer comprising a first frequency mixing unit that uses quadrature LO signals having respective phases of 0 degrees and 180 degrees to directly down-convert the single phase RF signal into the in-phase baseband signal, and a second frequency mixing unit that uses quadrature LO signals having respective phases of 90 degrees and 270 degrees to directly down-convert the single phase RF signal into the quadrature-phase baseband signal, whereby drains and sources of the transistor for receiving the quadrature LO signal and the transistor for receiving the RF signal are connected in common, thus enabling low power source voltage driving.

Abstract: Provided is a wideband active balun circuit based on a differential amplifier. The active balun circuit is configured to compensate for unbalance between two differential signals and can be applied to wideband systems, such as software defined radio (SDR) systems or ultra wideband (UWB) systems. Also, when signal unbalance is caused by changes in process conditions, such as temperature, errors in amplitude and phase between the two differential signals can be finely tuned by adjusting a voltage tuning terminal outside a chip, so that the active balun circuit can simply solve the unbalance between the two differential signals. Furthermore, input transistors that constitute a pair of differential amplifiers are provided in a cascode structure to prevent the occurrence of signal leakage and self-mixture.

Abstract: Provided is a mobile transmitter and a transmitting method thereof. The mobile transmitter includes a transmission circuit and a control circuit. The transmission circuit selectively operates as a polar transmitter or a direct-conversion transmitter. The control circuit controls an operation of the transmission circuit based on the level of an output signal. The mobile transmitter operates as a direct-conversion transmitter using a linear power amplifier with a high dynamic range when it transmits a low-power signal. Also, the mobile transmitter operates as a polar transmitter using a switching power amplifier with a high power efficiency when it transmits a medium-power or high-power signal. Thus, the mobile transmitter according to the present invention can provide both the high power efficiency (i.e., the advantage of the switching power amplifier) and the high dynamic range (i.e., the advantage of the linear power amplifier).

Abstract: Provided is a low power consuming mixed mode amplifier.

Abstract: Provided is a voltage controlled oscillator to which a switching bias technique is applied so as to lower flicker noise of a bias circuit and enhance phase noise characteristics, thereby reducing the overall chip area to make it possible to achieve integration. A common mode voltage applied to the bias circuit is negatively fed back to an oscillation waveform. Therefore, it is possible to stabilize the magnitude of the oscillation waveform of the voltage controlled oscillator with respect to a change in an external condition.

Abstract: Provided is a wideband active balun circuit based on a differential amplifier. The active balun circuit is configured to compensate for unbalance between two differential signals and can be applied to wideband systems, such as software defined radio (SDR) systems or ultra wideband (UWB) systems. Also, when signal unbalance is caused by changes in process conditions, such as temperature, errors in amplitude and phase between the two differential signals can be finely tuned by adjusting a voltage tuning terminal outside a chip, so that the active balun circuit can simply solve the unbalance between the two differential signals. Furthermore, input transistors that constitute a pair of differential amplifiers are provided in a cascode structure to prevent the occurrence of signal leakage and self-mixture.

Abstract: A display device having a cable card is provided wherein the cable card stores firmware, an interface that receives homing information from a service provider, an update part that updates the cable card firmware according to the homing information, a storage part that stores node information about at least one corresponding node, a message generator that generates a message indicating an update of the firmware of the cable card, and a communication part that transmits the message to the at least one corresponding node. The corresponding node information may be a phone number and the communication part can access a short messenger service center to transmit an SMS text message to the corresponding node. Accordingly, a user can be easily aware of the firmware update.

Abstract: An audio apparatus comprising a speaker to output an audio signal. The apparatus comprises an audio signal receiver which receives an input audio signal, a signal processor for processing the input audio signal and providing an output audio signal, an audio connection terminal to which the output audio signal processed in the signal processor is output, and a controller for determining whether an external device is connected to the audio connection terminal. The audio apparatus controls the signal processor to output the output audio signal to the audio connection terminal when it is determined that the external device is connected to the audio connection terminal. Thus, the present invention provides an audio apparatus which is capable of improving sound quality of an output audio signal by selectively outputting the audio signal, and a control method thereof.

Abstract: In a multilayer RF module, a plurality of vertically stacked ceramic layers include a first to a third ceramic layers. Each of the first and the third ceramic layers has a circuit component thereon and the second ceramic layer is located between the first and the third ceramic layers and is provided with at least one or more air cavities filled with air, the air cavities being vertically aligned with the circuit components of the first and the third ceramic layers.