Abstract: Provided is a polar transmitter which increases a modulation rate using a multi-phase generator and includes: a data processor which processes and separates incoming data to an amplitude component and a phase component; a multi-phase generator which generates a plurality of carriers having a plurality of phase components by processing a carrier having a certain frequency; a selection output part which selects and outputs a carrier having a phase substantially equal to the phase component; and a carrier output part which synthesizes the output carrier with the amplitude component and outputs a carrier. Accordingly, the modulation rate of the carrier can be increased and the bandwidth can be extended with the related art polar transmitter. Therefore, the polar transmitter is applicable to the wideband communications, the multi-mode, and the multi-band.

Abstract: A frequency synthesizing apparatus and method for a multi-band radio frequency (RF) receiver is provided. The frequency synthesizing apparatus includes a simple circuit configuration with a single SSB mixer and thus, may synthesize six high frequency signals. Signals to be inputted into the SSB mixer include a first signal and a second signal. The first signal is generated based on a VCO and a PPF. Also, the second signal is selected from a plurality of frequency divided signals which are generated by dividing a signal generated in the VCO via a plurality of dividers.

Abstract: A frequency synthesizing apparatus and method for a multi-band radio frequency (RF) receiver is provided. The frequency synthesizing apparatus includes a simple circuit configuration with a single SSB mixer and thus, may synthesize six high frequency signals. Signals to be inputted into the SSB mixer include a first signal and a second signal. The first signal is generated based on a VCO and a PPF. Also, the second signal is selected from a plurality of frequency divided signals which are generated by dividing a signal generated in the VCO via a plurality of dividers.

Abstract: A multi-input multi-frequency synthesizing apparatus and method for a multi-band radio frequency (RF) receiver. The frequency synthesizing apparatus may generate an output from a greater number of high frequency signals by using one multi-input single side band (SSB) mixer. The multi-input SSB mixer may generate a signal whose frequency is an addition of frequencies of two signals selected from a signal selection control unit, or a difference of frequencies therebetween. According to a circuit configuration of the multi-input SSB mixer, the signal selection control unit may select more than two signals.

Abstract: An apparatus and method for converting a frequency of a high frequency signal received from an antenna in an ultra wide band communication system transmitting and receiving using at least two reference frequencies. The method includes generating generation frequencies having frequencies set to convert the frequency of the high frequency signal and mixing the frequency of the high frequency signal and the generation frequencies in at least two stages.

Abstract: A frequency synthesizing apparatus and method for a multi-band radio frequency (RF) receiver is provided. The frequency synthesizing apparatus includes a simple circuit configuration with a single SSB mixer and thus, may synthesize six high frequency signals. Signals to be inputted into the SSB mixer include a first signal and a second signal. The first signal is generated based on a VCO and a PPF. Also, the second signal is selected from a plurality of frequency divided signals which are generated by dividing a signal generated in the VCO via a plurality of dividers.

Abstract: Integrated circuit devices include a pair of field effect transistors having shared source terminals, shared drain terminals and shared gate terminals, which may be treated herein as being electrically coupled in parallel. A switch circuit is also provided, which is configured to drive a body terminal of a first one of the pair of field effect transistors with an alternating sequence of first and second unequal body voltages. This alternating sequence is synchronized with a first clock signal. The switch circuit is also configured to drive a body terminal of a second one of the pair of field effect transistors with an alternating sequence of third and fourth unequal body voltages, which is synchronized with a second clock signal. The first and third body voltages may have equivalent magnitudes and the second and fourth body voltages may have equivalent magnitudes. The first and second clock signals may have 50% duty cycles and may be 180 degrees out-of-phase relative to each other.

Abstract: A receiver includes first switches for applying either differential signals of an oscillator or a data signal of a transmitter to down-converting mixers; a frequency conversion unit for mixing and applying to the down-converting mixers quadrature signals generated from an arbitrary clock signal generator and the oscillator, and having a PPF for changing a phase difference of I/Q signals according to a control voltage externally applied; a phase difference detection part for checking a phase difference between the I/Q signals and generating the control voltage to be applied to the PPF according to the phase difference so as to correct the phase difference; third switches for applying the data signal processed through the down-converting mixers, filters, and amplifiers to A/D converters and applying the I/Q signals having a predetermined frequency to the phase difference detection part; and a control unit for switching the first and third switches.

Abstract: A quadrature signal generator capable of phase-tuning with respect to all of four generated quadrature signals. The quadrature signal generator includes four phase tuning units each having two input terminals, one receiving a differential signal, the other being grounded, and changing a phase of the differential signal to thereby generate quadrature signals. Accordingly, it is possible to tune phases of all the four generated quadrature signals. It is also possible to prevent the amplitude of quadrature signals from being deviated from a reference value.

Abstract: An ultra wideband filter is provided that filters an input signal using a pair of cross-coupled transistors with a small size and small power consumption. The ultra wideband filter includes a reference current generator unit generating a reference current using a bias signal of a predetermined level, a transconductor unit that is biased by the reference current and converts a predetermined input voltage into a current of a predetermined amount to output the current if the input voltage is applied thereto, and a filter unit that outputs a predetermined output voltage corresponding to the output current of the transconductor unit using a plurality of cross-coupled transistors and capacitors. The filter unit may include cross-coupled nMOS and pMOS transistors, and first and second capacitors respectively connected to respective drain terminals of the nMOS and pMOS transistors. Accordingly, the ultra wideband filter can be designed in a minimum size.

Abstract: A polar transmitter using a binary phase shift key (BPSK) method includes a data dividing unit which divides input data into an amplitude component and a phase component, a frequency synthesizer which produces an I value of a passband having a phase component of an I signal and a Q value of a passband having a phase component of a Q signal, a polar modulation circuit for the I signal which produces an I carrier wave to the I signal using the amplitude component from the data dividing unit and the I value from the frequency synthesizer, a polar modulation circuit for the Q signal which produces a Q carrier wave to the Q signal using the amplitude component and the Q value, and a carrier wave producing unit which combines the I carrier wave and the Q carrier wave thus to produce a carrier wave.

Abstract: Provided is a polar transmitter which increases a modulation rate using a multi-phase generator and includes: a data processor which processes and separates incoming data to an amplitude component and a phase component; a multi-phase generator which generates a plurality of carriers having a plurality of phase components by processing a carrier having a certain frequency; a selection output part which selects and outputs a carrier having a phase substantially equal to the phase component; and a carrier output part which synthesizes the output carrier with the amplitude component and outputs a carrier. Accordingly, the modulation rate of the carrier can be increased and the bandwidth can be extended with the related art polar transmitter. Therefore, the polar transmitter is applicable to the wideband communications, the multi-mode, and the multi-band.

Abstract: The present invention relates to a distributed oscillator, and more particularly, to a high frequency distributed oscillator using coupled transmission lines. According to the present invention, coupled transmission lines capable of increasing the frequency selectivity are used as transmission lines. Signal interference occurs among the coupled transmission lines because of mutual approximation. The coupled transmission lines serve as a filter due to the signal interference. A phase noise characteristic can be thus increased.

Abstract: A probe is provided for an SPM (Scanning Probe Microscope), and a method is provided for fabricating the probe in which a double side alignment process is not required to simplify the fabricating. The probe includes a cantilever; a body supporting the cantilever; and a tip formed at an end of the cantilever, wherein the cantilever, the body and the tip are made of silicon, and boron is diffused into the cantilever and a predetermined area of the body.

Abstract: A receiver includes first switches for applying either differential signals of an oscillator or a data signal of a transmitter to down-converting mixers; a frequency conversion unit for mixing and applying to the down-converting mixers quadrature signals generated from an arbitrary clock signal generator and the oscillator, and having a PPF for changing a phase difference of I/Q signals according to a control voltage externally applied; a phase difference detection part for checking a phase difference between the I/Q signals and generating the control voltage to be applied to the PPF according to the phase difference so as to correct the phase difference; third switches for applying the data signal processed through the down-converting mixers, filters, and amplifiers to A/D converters and applying the I/Q signals having a predetermined frequency to the phase difference detection part; and a control unit for switching the first and third switches.

Abstract: An ultra wideband filter is provided that filters an input signal using a pair of cross-coupled transistors with a small size and small power consumption. The ultra wideband filter includes a reference current generator unit generating a reference current using a bias signal of a predetermined level, a transconductor unit that is biased by the reference current and converts a predetermined input voltage into a current of a predetermined amount to output the current if the input voltage is applied thereto, and a filter unit that outputs a predetermined output voltage corresponding to the output current of the transconductor unit using a plurality of cross-coupled transistors and capacitors. The filter unit may include cross-coupled nMOS and pMOS transistors, and first and second capacitors respectively connected to respective drain terminals of the nMOS and pMOS transistors. Accordingly, the ultra wideband filter can be designed in a minimum size.

Abstract: A quadrature signal generator capable of phase-tuning with respect to all of four generated quadrature signals. The quadrature signal generator includes four phase tuning units each having two input terminals, one receiving a differential signal, the other being grounded, and changing a phase of the differential signal to thereby generate quadrature signals. Accordingly, it is possible to tune phases of all the four generated quadrature signals. It is also possible to prevent the amplitude of quadrature signals from being deviated from a reference value.

Abstract: The present invention relates to a distributed oscillator, and more particularly, to a high frequency distributed oscillator using coupled transmission lines. According to the present invention, coupled transmission lines capable of increasing the frequency selectivity are used as transmission lines. Signal interference occurs among the coupled transmission lines because of mutual approximation. The coupled transmission lines serve as a filter due to the signal interference. A phase noise characteristic can be thus increased.

Abstract: An apparatus and method for converting a frequency of a high frequency signal received from an antenna in an ultra wide band communication system transmitting and receiving using at least two reference frequencies. The method includes generating generation frequencies having frequencies set to convert the frequency of the high frequency signal and mixing the frequency of the high frequency signal and the generation frequencies in at least two stages.

Abstract: A probe is provided for an SPM (Scanning Probe Microscope), and a method is provided for fabricating the probe in which a double side alignment process is not required to simplify the fabricating. The probe includes a cantilever; a body supporting the cantilever; and a tip formed at an end of the cantilever, wherein the cantilever, the body and the tip are made of silicon, and boron is diffused into the cantilever and a predetermined area of the body.