Abstract: A method of generating multi-channel local oscillation frequencies in an ultra wide band communication system includes generating: at least one reference frequency, a plurality of auxiliary frequencies by dividing and multiplying the at least one reference frequency, and a plurality of first local oscillation frequencies by mixing the reference frequency and at least some of the plurality of auxiliary frequencies with other auxiliary frequencies.

Abstract: A balun transformer includes a first conductive pattern having one end provided as an input/output port of an unbalanced signal, a second conductive pattern electromagnetically coupled to the first conductive pattern and having both ends provided as input/output ports of a balanced signal, and a first variable capacitor connected between a ground part and a middle part of an electrical length of the second conductive pattern.

Abstract: Disclosed is a wireless communication system applicable to a time-division duplex transceiver system. The time-division duplex mobile communication system can achieve miniaturization, low power consumption and low costs by using a frequency conversion circuit including a mixer and an intermediate frequency (IF) circuit for both transmitter and receiver, and also can cope with multi-band, multi-application systems by using a broadband amplifier, a variable IF filter and a variable gain amplifier.

Abstract: Disclosed is a wireless communication system applicable to a time-division duplex transceiver system. The time-division duplex mobile communication system can achieve miniaturization, low power consumption and low costs by using a frequency conversion circuit including a mixer and an intermediate frequency (IF) circuit for both transmitter and receiver, and also can cope with multi-band, multi-application systems by using a broadband amplifier, a variable IF filter and a variable gain amplifier.

Abstract: A super-regenerative receiver including a super-regenerative oscillator is disclosed. The super-regenerative receiver includes a super-regenerative oscillator for generating an oscillation signal when receiving driving current exceeding a predetermined critical level. The receiver also includes a bias current controller for generating bias current according to an output of the super-regenerative oscillator, and a pulse width controller for receiving a predetermined clock and controlling a width of the clock according to the output of the super-regenerative oscillator. The super-regenerative receiver further includes a quench generator receiving the width-controlled clock from the pulse width controller and generating quench current that varies according to the pulse width of the clock. The driving current for oscillation equals to a sum of the bias current N-times multiplied and the quench current.

Abstract: A variable gain amplifier including: a differential amplification unit amplifying and outputting a difference between a first input signal and a second input signal inputted via a first input terminal and a second input terminal, respectively, according to a first bias current of the first input terminal and second input terminal, to a first output terminal and a second output terminal; a diode-connected load unit comprising loads diode-connected to the first output terminal and second output terminal, respectively, the load receiving a second bias current; and a gain control unit controlling a gain between the input terminals and the output terminals of the differential amplification unit by controlling the size of the first bias current and second bias current.

Abstract: There is provided a variable gain amplifier that is implemented with a CMOS device and has wide band variation and wide bandwidth by a predetermined exponential function. A variable gain amplifier having wide gain variation and wide bandwidth according to an aspect of the invention may include: a differential amplification section differentially amplifying an input signal according to a gain adjustment signal; and a gain adjustment section supplying the gain adjustment signal on the basis of an approximated exponential function determined according to a predetermined bias current, and adjusting a gain of the differential amplification section.

Abstract: A balun transformer includes a first conductive pattern having one end provided as an input/output port of an unbalanced signal, a second conductive pattern electromagnetically coupled to the first conductive pattern and having both ends provided as input/output ports of a balanced signal, and a first variable capacitor connected between a ground part and a middle part of an electrical length of the second conductive pattern.

Abstract: A method of generating multi-channel local oscillation frequencies in an ultra wide band communication system having multiple channels of identical bandwidth, the method including: generating at least one reference frequency; generating a plurality of auxiliary frequencies by dividing and multiplying the at least one reference frequency; and generating a plurality of first local oscillation frequencies by mixing the reference frequency and at least some of the plurality of auxiliary frequencies with other auxiliary frequencies, respectively, wherein each of the auxiliary frequencies used in the mixing is greater than an interval between the frequency being mixed and an outermost frequency in the ultra wide band.

Abstract: Disclosed herein is an apparatus and method for calibrating displacement of reflective parts. The apparatus includes memory, a sampling data output unit, an optical modulator drive circuit, a light detection unit, a control unit, and a calibration value calculation unit. The calibration value calculation unit receives a measured light intensity value, and outputs a constructed element-based calibration data.

Abstract: A quadrature voltage-controlled oscillator comprises a first delay cell outputting first and second phase signals having a different phase; and a second delay cell outputting third and fourth phase signals having a different phase, the third and fourth phase signals crossing the first and second phase signals, respectively. The first delay cell includes a first differential voltage-controlled oscillator connected to a power supply and outputting the first and second phase signals; and a first coupling section including first and second coupling transistors connected to the first differential voltage-controlled oscillator and first and second coupling capacitors connected in parallel to the first and second coupling transistors, respectively, so as to be grounded, the first coupling section coupling the output phase signals.

Abstract: A super-regenerative receiver including a super-regenerative oscillator is disclosed. The super-regenerative receiver includes a super-regenerative oscillator for generating an oscillation signal when receiving driving current exceeding a predetermined critical level. The receiver also includes a bias current controller for generating bias current according to an output of the super-regenerative oscillator, and a pulse width controller for receiving a predetermined clock and controlling a width of the clock according to the output of the super-regenerative oscillator. The super-regenerative receiver further includes a quench generator receiving the width-controlled clock from the pulse width controller and generating quench current that varies according to the pulse width of the clock. The driving current for oscillation equals to a sum of the bias current N-times multiplied and the quench current.