| Patent application number | Description | Published |
|---|
| 20090115516 | NAUTA OPERATIONAL TRANSCONDUCTANCE AMPLIFIER - Provided is an operational transconductance amplifier (OTA). An existing Nauta transconductor used to implement a high frequency Gm-C filter integrated circuit (IC) is analyzed by a new method and from a new perspective to remove extra components and divide roles of remaining inverters for more simple and efficient circuit structure. In an existing Nauta transconductor, a common mode signal from an input terminal is amplified and appears at an output terminal, while in the inventive Nauta transconductor the common mode signal from an input terminal does not appear at the output terminal and is effectively eliminated. These enhanced characteristics can be achieved with a smaller number of inverters than an existing Nauta transconductor. Frequency characteristics of the filter can be effectively enhanced by independently controlling the quality factor without affecting the transconductance value required for frequency characteristics of the filter. | 05-07-2009 |
| 20100134192 | FREQUENCY CALIBRATION LOOP CIRCUIT - A frequency calibration loop circuit having a pre-set frequency channel word (FCW) command value, a bit inputted to obtain a target frequency in an oscillator and a pre-set minimum division ratio n (n is a constant) of a programmable divider, includes: an oscillator adjusting a oscillation frequency according to control value; a programmable divider dividing the oscillation frequency according to a division ratio; a counter counting the number of clocks of the divided frequency by using a reference frequency; and a frequency detector outputting a value obtained by subtracting the number of the counted clocks from a reference comparison value, a value obtained by dividing a Frequency Channel Word (FCW) command value by a minimum division ratio of the programmable divider, as the control value of the oscillator. | 06-03-2010 |
| 20100201457 | HYBRID BALUN APPARATUS - A hybrid balun apparatus are disclosed. The hybrid balun apparatus can support both the reception mode and the transmission mode and be advantageous for a high level of integration, by replacing two transformers disposed at a reception path and a transmission path with a single transformer and integrating a T/R switch and a balun into a one chip. Therefore, an IC according to integration extends to a front stage of an antenna to facilitate interfacing between elements, and a burden for designing at a rear stage (i.e., LNA in the reception mode, and PA in the transmission mode) can be reduced. | 08-12-2010 |
| 20100271072 | DIGITAL LOCK DETECTOR AND FREQUENCY SYNTHESIZER USING THE SAME - There is provided a digital lock detector and a frequency synthesizer using the same. The digital lock detector includes a comparator unit receiving a plurality of control bits, and generating a bit signal to notice a lock condition of the plurality of control bits; a delay cell block generating a plurality of delay signals based on the bit signal, and outputting a clock signal by combining the bit signal and the plurality of delay signals; and a detection unit detecting a shift time of the clock signal, and generating a lock indication signal according to the detection result. | 10-28-2010 |
| 20110026571 | AUTOMATIC GAIN CONTROLLER, TRANSCEIVER AND AUTOMATIC GAIN-CONTROL METHOD THEREOF - An automatic gain-control method for a communication system is comprised of determining a communication distance between the first and second transceivers and controlling gain values of transception stages of the first and second transceivers in correspondence with the communication distance. | 02-03-2011 |
| 20110032044 | THE DIFFERENTIAL VCO AND QUADRATURE VCO USING CENTER-TAPPED CROSS-COUPLING OF TRANSFORMER - Provided are a differential voltage-controlled oscillator (VCO) and a quadrature VCO using center-tapped cross-coupling of a transformer. The differential VCO and the quadrature VCO can be driven by low power through a current reuse structure and have an excellent phase noise characteristic by center-tapped cross-coupling through a transformer. Further, variable capacitance units for frequency variation are divided into variable capacitance units for coarse tuning and variable capacitance units for fine tuning. Therefore, it is possible to obtain a wide tuning range while voltage oscillation gain is reduced. Further, the differential VCO and the quadrature VCO are configured in such a manner that the respective variable capacitance units operate linearly throughout the entire capacitance region due to control voltage distribution by resistors. Accordingly, it is possible to obtain a linear control voltage-oscillation frequency characteristic. The quadrature VCO according to the present invention can output four-phase quadrature signals while having an excellent phase noise characteristic, without substrate loss and current consumption caused by the switching transistors. | 02-10-2011 |
