| Patent application number | Description | Published |
|---|
| 20090021331 | STEP ATTENUATOR - There is provided a step attenuator having two Pi-type attenuators and one bridged-T type attenuator that share some resistors. The step attenuator is used to prevent a reduction in frequency range caused by use of MOS transistors and reduce attenuation of signal power and frequency band by the MOS transistors, thereby obtaining a low attenuation value and reducing input and output mismatch. | 01-22-2009 |
| 20090066425 | FREQUENCY SYNTHESIZER HAVING MULTI-BAND VOLTAGE CONTROLLED OSCILLATOR - There is provided a frequency synthesizer including a multi-band voltage controlled oscillator having a plurality of voltage controlled oscillating cores outputting oscillation frequencies having different bands according to an input control voltage. Each of the voltage controlled oscillating cores outputs a frequency band divided into a plurality of bands, and the voltage controlled oscillating core operates by each of the divided bands, and one of the voltage controlled oscillating cores operates in one of the bands according to the control voltage. The frequency synthesizer further includes a comparator unit and an oscillation band-determining unit. The comparator unit compares the control voltage with a pre-set reference voltage range. The oscillation band-determining unit changes the band where the voltage controlled oscillating core operates into another one of the bands when the control voltage is out of the pre-set reference voltage range. | 03-12-2009 |
| 20090153256 | FREQUENCY GENERATOR - There is provided a feedback circuit including: an oscillator generating an oscillation frequency signal; a mixer unit having an input terminal, a feedback terminal, and an output terminal and outputting a frequency signal through the output terminal, the frequency signal obtained by adding or subtracting frequency of a feedback signal, input through the feedback terminal, to or from frequency of the oscillation frequency signal input through the input terminal from the oscillator; a first frequency divider dividing the frequency signal output from the mixer unit at a division ratio of N (N is a multiple of 2) to generate an output signal; and a feedback circuit adjusting the output signal of the first frequency divider for the first frequency divider to output a frequency signal in a desired band and feeding back the adjusted signal to the feedback terminal of the mixer unit. | 06-18-2009 |
| 20100073040 | FREQUENCY DIVIDER USING LATCH STRUCTURE - There is provided a frequency divider using a latch structure including: a first latch sampling and latching an input signal in response to a first clock signal and a second clock signal having an inverse phase with respect to the first clock signal; a second latch toggled with the first latch, the second latch sampling and latching the input signal in response to the first and second clock signals; a bias adjustor generating a sampling bias current and a latching bias current to supply to the first and second latches, respectively and adjusting a relative ratio between the sampling bias current and the latching bias current to vary a minimum power point oscillating frequency of the first and second latches. | 03-25-2010 |
| 20100134188 | BUFFER AMPLIFIER - A buffer amplifier has high input impedance and is less affected by temperature by supplying independent bias power to each of amplification units. The buffer amplifier includes a bias supply unit supplying bias power having a preset voltage level, an amplification unit receiving preset driving power and the bias power from the bias supply unit to amplify an input signal, and a compensation unit compensating for current unbalance of the driving power supplied to the amplification unit. | 06-03-2010 |
| 20110037507 | MIXER WITH DIFFERENTIAL DC OFFSET CANCELLATION FUNCTION - A mixer with a differential DC offset cancellation function includes: a load unit including a first load unit and a second load unit; a mixing unit biased by current transferred from the load unit to mix inputs signal and oscillation signals; a first output voltage detection unit detecting an output voltage of the first output terminal; a second output voltage detection unit detecting an output voltage of the second output terminal; a first injection/extraction circuit unit injecting current into the first load unit or extracting current from the first load unit according to the size of a first detection voltage; a second injection/extraction circuit unit injecting current into the second load unit or extracting current from the second load unit according to the size of a second detection voltage; and a current regulation unit regulating an overall current flowing across the first and second injection/extraction circuit units. | 02-17-2011 |
| 20110156813 | POWER AMPLIFIER - There is provided a power amplifier that can maintain a constant gain by detecting a level of a signal being input and a level of a signal being output. A power amplifier according to an aspect of the invention may include: an amplification section having at least one amplification unit amplifying an input signal according to an adjustable gain to thereby output the amplified input signal; a detection section detecting signal levels of an input signal and an output signal of the amplification section; and a gain maintaining section controlling a bias power according to a detection result of the detection section so that a gain of the amplification section is maintained within a predetermined gain range. | 06-30-2011 |
| 20110304398 | CMOS POWER AMPLIFIER AND TEMPERATURE COMPENSATION CIRCUIT THEREOF - Disclosed is a CMOS power amplifier. A temperature compensation circuit of a CMOS power amplifier may include: a bias circuit unit supplying a gate bias voltage to a power amplification circuit part; a bias detection unit determining a class type of the power amplification circuit part according to the gate bias voltage; a temperature detection unit detecting a temperature-proportional voltage in proportion to ambient temperature; a temperature compensation control unit generating a compensation control value according to the temperature-proportion voltage in the class type determined by the bias detection unit; and a conversion unit converting the compensation control value of the temperature compensation control unit into a linear bias control value and providing the linear bias control value to the bias circuit unit, wherein the bias circuit unit compensates the gate bias voltage according to the linear bias control value of the conversion unit. | 12-15-2011 |
