Abstract: A filter comprises a series unit, and a shunt unit disposed between the series unit and a ground. The shunt unit includes resonators that are selectively operated, and each of the shunt resonators includes a film bulk acoustic resonator.

Abstract: A filter module includes filters. Each of the filters is configured to control communications bands having overlapping bandwidths each with the other. Each of the communications bands, allocated to any one of the filters, has a different limit frequency from the other.

Abstract: A filter module includes filters. Each of the filters is configured to control communications bands having overlapping bandwidths each with the other. Each of the communications bands, allocated to any one of the filters, has a different limit frequency from the other.

Abstract: A filter comprises a series unit, and a shunt unit disposed between the series unit and a ground. The shunt unit includes resonators that are selectively operated, and each of the shunt resonators includes a film bulk acoustic resonator.

Abstract: There are provided a communications interface apparatus and a method of operating the same. The communications interface apparatus includes: a transmission line including a conductor line and a plastic optical fiber for optical communications; a signal transmitting unit transmitting a first data signal through the plastic optical fiber and transmitting a second data signal through the conductor line; and a signal receiving unit receiving the first data signal and the second data signal, wherein the signal transmitting unit differentiates a signal as the first data signal or the second data signal based on at least one of a level and a frequency of the signal to be transmitted.

Abstract: Disclosed herein is a power measurement system capable of power of electric devices without performing a quantization process through a separate analog-digital converter for voltage. The power measurement system includes a smart meter measuring a voltage root mean square value input to an electrical device; and a power measurement device measuring power of the electrical equipment using a voltage root mean square value Vrms measured by the smarter meter and a current instantaneous values of power lines connected to the electric device.

Abstract: There is provided an apparatus for detecting the coordinates of an event within an interest region including: a light source limiting an interest region; at least two light receiving units receiving reflected light of an event within the interest region; a reflector refracting the reflected light received in the light receiving units; and one image sensor on which the reflected light refracted on the reflector is image-formed, wherein the apparatus for detecting coordinates is configured of one module.

Abstract: Disclosed is a touch screen to accurately receive a user selection by applying differential signals to the electrode patterns of a touch screen, each having a different capacitance.

Abstract: A downconverter and upconverter are provided which can obtain a sufficient image rejection ratio in a low-Intermediate Frequency (IF) scheme while reducing power consumption and can suppress Error Vector Magnitude (EVM)-related degradation in a zero-IF scheme. A complex-coefficient transversal filter rejects one side of a positive or negative frequency, and converts a Radio Frequency (RF) signal to a complex RF signal configured by real and imaginary parts. A local oscillator outputs a real local signal with a set frequency. A half-complex mixer, connected to the complex-coefficient transversal filter and the local oscillator, performs a frequency conversion process by multiplying the complex RF signal output from the complex-coefficient transversal filter and the real local signal output from the local oscillator, and outputs a complex signal of a frequency separated by the set frequency from a frequency of the RF signal.

Abstract: A derivative superposition circuit for linearization includes a first active element that is provided with first to third terminals and in which the magnitude and direction of current flowing from the second terminal to the third terminal changes on the basis of the magnitude of a voltage applied between the first and second terminals; and a second active element that is provided with first to third terminals and has complementary characteristics with the first active element. The first terminals of the first and second active elements are connected to each other so that a predetermined operational bias voltage is maintained by first and second power supplies through a first impedance, and are connected to an input end through a second impedance. The third terminals of the first and second active elements are connected to an output end, and the second terminals of the first and second active elements are connected to the second power supply through a third impedance.

Abstract: The present invention relates to an exponential function generator which is realized with only CMOS element without BJT element, not limited by the physical properties of the element or a square circuit, and not complicated in its configuration, and a variable gain amplifier using the same. The exponential function generator includes a voltage-current converter, 1st to nth curve generators for mirroring the current from the voltage-current converter, outputting a current adjusted according to a predetermined ratio, and an output end for outputting the sum of the current from the 1st to nth curve generators. The exponential current generator is configured to generate the current exponentially adjusted according to the control voltage.

Abstract: The invention relates to a feedback or feedforward type variable gain wideband amplifier. The variable gain wideband amplifier includes a feedback-type inversion amplifier circuit 310 for amplifying input Vin, a feedback-type non-inversion amplifier circuit 320 for amplifying input Vin, a power source circuit 330 for controlling the gain of the non-inversion amplifier circuit 320 and a load circuit 340 connected between a junction of output terminals of the inversion and non-inversion amplifier circuits 310 and 320 and power voltage potential VDD to control the gain of the amplifier circuits 310 and 320. The variable gain wideband amplifier of the invention is feedforward type, and outputs signals from the inversion and non-inversion amplifier circuits 310 and 320 via a single output terminal in order to attenuate third order intermodulation frequency IM3 generated from the amplifier circuits 310 and 320. Then, predetermined frequencies f1 and f2 included in the input signal are amplified.

Abstract: In a quadrature voltage controlled oscillator, a first oscillator includes a first resonant circuit for generating a preset first resonant frequency and a first pair of cross-coupled transistors for supplying energy to the first resonant frequency to generate first and second signals having a phase difference of 180°. A second oscillator includes a second resonant circuit for generating a preset second resonant frequency and a second pair of cross-coupled transistors for generating third and fourth signals for supplying energy to the second resonant frequency having a phase difference of 180°. A first current source is connected between a first common node of the first cross-coupled transistor pair and a ground. A second current source is connected between a second common node of the second cross-coupled transistor pair and the ground. A differential load is connected between a third common node of the first and second current sources and the ground.

Abstract: The present invention relates to a derivative superposition circuit for linearization. The derivative superposition circuit for linearization includes a first active element that is provided with first to third terminals and in which the magnitude and direction of current flowing the second terminal to the third terminal changes on the basis of the magnitude of a voltage applied between the first and second terminals; and a second active element that is provided with first to third terminals and has complementary characteristics with the first active element. The first terminals of the first and second active elements are connected to each other so that a predetermined operational bias voltage is maintained by first and second power supplies through a first impedance, and are connected to an input end through a second impedance.

Abstract: The present invention relates to a terrestrial DMB receiver capable of eliminating image noise and minimizing the number of external elements. In the invention, a terrestrial DMB signal is down-converted into a baseband I/Q signal and then up-converted into a predetermined intermediate frequency signal. The invention solves the problematic image noise and minimizes the number of external elements at the same time.

Abstract: A downconverter and upconverter are provided which can obtain a sufficient image rejection ratio in a low-Intermediate Frequency (IF) scheme while reducing power consumption and can suppress Error Vector Magnitude (EVM)-related degradation in a zero-IF scheme. A complex-coefficient transversal filter rejects one side of a positive or negative frequency, and converts a Radio Frequency (RF) signal to a complex RF signal configured by real and imaginary parts. A local oscillator outputs a real local signal with a set frequency. A half-complex mixer, connected to the complex-coefficient transversal filter and the local oscillator, performs a frequency conversion process by multiplying the complex RF signal output from the complex-coefficient transversal filter and the real local signal output from the local oscillator, and outputs a complex signal of a frequency separated by the set frequency from a frequency of the RF signal.

Abstract: Disclosed herein is a digital automatic fine tuning method and apparatus, which is capable of detecting a difference between a nominal frequency and an intermediate frequency generated in a tuner using a counter, and applying the counted data of the counter as a fine tuning value for the intermediate frequency without using a decoder by controlling the reset and preset operations of the counter that counts the frequency of the intermediate frequency.

Abstract: Disclosed herein is a digital automatic fine tuning method and apparatus, which is capable of detecting a difference between a nominal frequency and an intermediate frequency generated in a tuner using a counter, and applying the counted data of the counter as a fine tuning value for the intermediate frequency without using a decoder by controlling the reset and preset operations of the counter that counts the frequency of the intermediate frequency.