Abstract: There is provided a dual mode WPAN transceiver including a dual mode WPAN transmitter and a dual mode WPAN receiver.

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: In a voltage controlled oscillator, a resonant circuit generates a resonant frequency in response to a tuning voltage. A differential oscillator includes first and second transistors differentially cross-coupled to the resonant circuit. The first and second transistors supply energy to the resonant circuit to oscillate the resonant frequency from the resonant circuit, thereby generating first and second oscillation signals having a phase difference of 180 degree. Also, the first and second transistors adjust the first and second oscillation signals to a uniform level in response to a body bias voltage. In addition, an output level detector detects a level of the first and second oscillation signals from the differential oscillator and supplies the body bias voltage corresponding to the detected level to a body of each of the first and second transistors.

Abstract: There is provided an RC oscillation circuit capable of adjusting an oscillation frequency, and an oscillation method thereof. The RC oscillation circuit including: an RC oscillator including a variable resistor and a variable capacitor, the RC oscillator generating an RC oscillating signal having a frequency determined by a resistance of the variable resistor and a capacitance of the variable capacitor; a counter counting a clock number of a reference oscillating signal corresponding to one period of the RC oscillating signal to generate a first count value, the reference oscillating signal having a preset frequency; and a frequency controller controlling a frequency of the RC oscillating signal by determining the resistance of the variable resistor and the capacitance of the variable capacitor such that a difference between the first count value and a preset second count value is smaller than a preset first critical value.

Abstract: A micropower RC oscillator comprises a current generating section including a current source that generates a current; and a variable resistor of which the magnitude is variably set and which is configured by combining resistor elements at a predetermined ratio, the resistor elements having opposite characteristics to each other with respect to a temperature change, the variable resistor adjusting the magnitude of the generated current; a start-up circuit section connected to the current generating section and fixing a bias operating point to a constant value such that the current generating section stably generates a current; a charge and discharge circuit section including a variable capacitor, of which the magnitude is variably set, and a plurality of transistors, the charge and discharge circuit section charging and discharging the variable capacitor by using the current generated from the current generating section and the plurality of transistors; an oscillation signal output section connected to the ch

Abstract: Disclosed is a wake-up system with passive correlators, adopted to wireless transmission/reception devices such as remote controllers, mobile communication terminals, etc. The wake-up system includes a transmitter and receiver. In the transmitter wake-up signals and delayed wake-up signals delayed by a predetermined delay time are correlated and coded, respectively, for transmission. In the receiver, signals transmitted from the transmitter and signals delayed by the predetermined delay time are correlated and decoded, respectively. The decoded signals are converted into DC switching voltage VSW for a switching operation of power, thereby performing a wake-up operation. The wake-up system with passive correlators can reduce consumption power for wake-up operations in a receiver such that correlation operations of a correlator including passive electrical elements such as a matched filter, etc.

Abstract: An oscillation stabilization detecting circuit comprises a T flip flop receiving a pulse-type oscillation signal generated by oscillating a crystal oscillator and then dividing the oscillation signal to output; a pulse control unit including inverters and transistors, the pulse control unit converting the signal output from the T flip flop into a pulse-type signal starting from a high level and then outputting the converted signal; and an oscillation stabilization detecting unit including a capacitor charged with the signal output from the pulse control unit; and a plurality of transistors. The oscillation stabilization detecting unit controls charging time of the capacitor by adjusting a bias current and, after the charging time passes, outputs a stabilization signal to a CPU, the stabilization signal representing that the oscillation signal is stabilized.

Abstract: There is disclosed a self-calibrating resistor-capacitor (RC) oscillator in which a resistor has a resistance value varied minimally by temperature change and process variation, a capacitor has a capacitance value selected adequately according to needs, and the resistor and capacitor are configurable as a one-chip by a complementary metal-oxide semiconductor (CMOS) process. The self-calibrating RC oscillator comprises a resistor part including a first resistor having a resistance value reduced with increase in temperature and a second resistor connected in series with the first resistor and having a resistance value increasing with increase in temperature.

Abstract: There is disclosed a voltage regulating apparatus with a short settling time and a small current consumption. The voltage regulating apparatus comprises a reference voltage generator including an MOSFET array comprising a plurality of MOSFETs with a structure in which a drain and a source are connected in series with each other, a supply voltage is applied to the drain of the MOSFET located in an end of the MOSFET array and the source of the MOSFET located in another end is grounded, and the reference voltage is a voltage obtained by dividing by the plurality of MOSFETs of the MOSFET array at a predetermined ratio.

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 sub-harmonic frequency conversion device includes: a voltage controlled oscillator for generating first to eighth oscillation frequency (LO) signals having a constant phase difference; a first mixer for performing a switching operation to mix the first to fourth LO signals having a phase difference of 90° and input signals, and outputting first IF signals; and a second mixer for performing a switching operation to mix the fifth to eighth LO signals having a phase difference of 90° and the input signals, and outputting second IF signals. Accordingly, the sub-harmonic frequency conversion device can use the low-frequency LO signal, and the power consumption can be reduced. In addition, because the mixers are implemented using a symmetric structure of the MOS transistors, the circuit configuration can be easily implemented.

Abstract: Provided is a low-power wireless communication apparatus and method. In the apparatus, a low-noise amplifier amplifies an RF signal in an on state, the low-noise amplifier be turned on/off according to a predetermined control signal. A wake-up signal detector detects a wake-up signal from the amplified RF signal. A controller provides the predetermined control signal such that the low-noise amplifier and the wake-up signal detector operate at a predetermined on-off duty ratio in a sleep mode corresponding to an Rx waiting state, and switching to an Rx mode to maintain the on state of the low-noise amplifier when the wake-up signal is detected.

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 timing estimator of an OQPSK demodulator is provided. In the timing estimator, an A/D converter converts an analog reception signal into a digital reception signal. A differential circuit section delays the digital reception signal from the A/D converter by a preset time and obtains a phase difference between a conjugate complex number signal of the delayed digital reception signal and the digital reception signal to offset a frequency error contained in the digital reception signal. A correlation operation section performs a correlation operation between a reference symbol differentiated in the same way as a differentiation of the differential circuit section and the reception signal to obtain each correlation value. A coherent detector detects a coherent point on the basis of the correlation value from the correlation operation section.

Abstract: The invention provides a transmitter using a chaotic signal which turns on/off a supply voltage of a chaotic signal generator in accordance with a transmitted digital data signal, without requiring a separate modulator for combining the chaotic signal and the digital data signal. The transmitter uses a chaotic signal for modulating a predetermined digital data to transmit. A chaotic signal generator turns on to generate the chaotic signal when a supply voltage is supplied and turns off when the supply voltage is cut off. A supply voltage switch supplies/cuts off the supply voltage to/from the chaotic signal generator in accordance with the digital data. Further, the supply voltage of the chaotic signal generator is supplied/cut off in accordance with the digital data so that an output from the chaotic signal generator is a modulated signal of the digital data.

Abstract: In a voltage controlled oscillator, a resonant circuit generates a resonant frequency in response to a tuning voltage. A differential oscillator includes first and second transistors differentially cross-coupled to the resonant circuit. The first and second transistors supply energy to the resonant circuit to oscillate the resonant frequency from the resonant circuit, thereby generating first and second oscillation signals having a phase difference of 180 degree. Also, the first and second transistors adjust the first and second oscillation signals to a uniform level in response to a body bias voltage. In addition, an output level detector detects a level of the first and second oscillation signals from the differential oscillator and supplies the body bias voltage corresponding to the detected level to a body of each of the first and second transistors.

Abstract: The invention relates to an ultra-low power high-efficiency wireless digital receiver which executes integration of a correlation signal of a reception signal without relying heavily on a high-power device like an amplifier, thereby reducing power consumption and attaining high sensitivity and efficiency. The receiver includes a SAW correlator having an internal correlation code corresponding to a conversion code of a transmitter and correlating the internal correlation code with a reception signal to provide a correlation signal. The receiver also includes a rectifier for rectifying the correlation signal from the SAW correlator, and an integrator for integrating the signal rectified by the rectifier to detect a voltage of the signal from the rectifier. The receiver further includes a comparator for comparing the voltage detected by the integrator and a predetermined reference voltage to output a digital signal according to the comparison result.

Abstract: The invention relates to a symbol detector for detecting symbols received in a receive modem of short-range wireless personal area network of a ZigBee system (IEEE 802.15.4). An OQPSK short-range wireless communication system according to the invention acquires frequency offset in a received signal using a symbol contained in a preamble of a packet of the signal, multi-delay-differentiates the signal by a plurality of predetermined delay times, and complex-conjugates the acquired frequency offset to eliminate the frequency offset. Then, the OQPSK short-range wireless communication system according to the invention correlates the received signal with a PN sequence delay-differentiated through the same process to detect the symbols corresponding to the received signal.

Abstract: A fading phenomenon is eliminated by integrally providing two monopole antennas on a printed circuit board, alternately feeding a high frequency signal to the two monopole antennas by a switching device, and differently forming distances and patterns of the two monopole antennas whereby making a diversity.