Abstract: An electronic device for synthesizing a frequency is provided. The electronic device includes a bank changer configured to output a channel code corresponding to a reference frequency signal and a feedback frequency signal, a channel code mapper configured to generate a changed channel code by applying an offset to the channel code output from the bank changer, and a voltage controlled oscillator configured to control a total capacitance of a plurality of capacitors based on the changed channel code and to oscillate a frequency dependent on the total capacitance.

Abstract: An analog baseband filter apparatus for a multi-mode and multi-band wireless transceiver and a method for controlling the analog baseband filter apparatus are provided. The analog baseband filter apparatus includes a plurality of Radio Frequency (RF) units, each of the plurality of RF units being for receiving RF signals of one of a plurality of frequency bands and outputting baseband signals, a plurality of filter blocks for filtering and amplifying the baseband signals, and a switching unit for connecting at least two of the plurality of RF units to at least one of the plurality of filter blocks according to a selected communication mode, wherein the at least one of the plurality of filter blocks is configured to be connected to a capacitor region of an adjacent filter block from among the plurality of filter blocks.

Abstract: A method and an apparatus are provided for setting a cut-off frequency of an analog filter of a reception device for wireless communication. A deviation value is obtained that corresponds to an error between a first gain value based on an ideal transfer function curve and a second gain value based on a measured transfer function curve at an arbitrary frequency of a frequency band in which a constant interval is maintained between a slope of the ideal transfer function curve and a slope of the measured transfer function curve. A cut-off frequency that is used to measure the measured transfer function curve in a real environment, is corrected based on the obtained deviation value.

Abstract: An Analog/Digital (A/D) modulation apparatus in a communication system supporting multiple communication modes and a method for controlling the same are provided. The A/D modulation apparatus includes an A/D modulation module having a structure in which a plurality of unit loops are extended by a serial connection, a control module configured to determine a modulation resolution needed for a communication mode to be used, a signal transfer control module including an input control module configured to transfer or block an intermediate output signal of a basic loop, as an input signal of an extended loop serially connected to the basic loop, in response to the modulation control bits provided from the control module, and an output module configured to generate a final digital-modulated signal based on a final output signal of the basic loop and a final output signal of the extended loop.

Abstract: An analog baseband filter apparatus for a multi-mode and multi-band wireless transceiver and a method for controlling the analog baseband filter apparatus are provided. The analog baseband filter apparatus includes a plurality of Radio Frequency (RF) units, each of the plurality of RF units being for receiving RF signals of one of a plurality of frequency bands and outputting baseband signals, a plurality of filter blocks for filtering and amplifying the baseband signals, and a switching unit for connecting at least two of the plurality of RF units to at least one of the plurality of filter blocks according to a selected communication mode, wherein the at least one of the plurality of filter blocks is configured to be connected to a capacitor region of an adjacent filter block from among the plurality of filter blocks.

Abstract: An analog baseband filter apparatus for a multi-mode and multi-band wireless transceiver and a method for controlling the analog baseband filter apparatus are provided. The analog baseband filter apparatus includes a plurality of Radio Frequency (RF) units, each of the plurality of RF units being for receiving RF signals of one of a plurality of frequency bands and outputting baseband signals, a plurality of filter blocks for filtering and amplifying the baseband signals, and a switching unit for connecting at least two of the plurality of RF units to at least one of the plurality of filter blocks according to a selected communication mode, wherein the at least one of the plurality of filter blocks is configured to be connected to a capacitor region of an adjacent filter block from among the plurality of filter blocks.

Abstract: An electronic device for synthesizing a frequency is provided. The electronic device includes a bank changer configured to output a channel code corresponding to a reference frequency signal and a feedback frequency signal, a channel code mapper configured to generate a changed channel code by applying an offset to the channel code output from the bank changer, and a voltage controlled oscillator configured to control a total capacitance of a plurality of capacitors based on the changed channel code and to oscillate a frequency dependent on the total capacitance.

Abstract: An operational amplifier circuit is provided. The operational amplifier circuit includes a differential amplifier of a cascade structure and a switched-capacitor type Common-Mode FeedBack (CMFB) circuit. The differential amplifier amplifies a difference between two input signals to output an anode output voltage and a negative output voltage. The switched-capacitor type CMFB circuit averages the anode output voltage and the negative output voltage of the differential amplifier, compares the average voltage with a reference voltage to generate a feedback signal based on a result of the comparison, and provides the feedback signal to the differential amplifier. Therefore, power consumption is reduced and a battery use time of a wireless terminal can be extended. Also, since an operational amplifier gain of each analog filter terminal is not negatively affected, a Direct Current (DC) offset is reduced, thereby improving signal quality.

Abstract: A method and an apparatus for calibration of a transmitter not having a Surface Acoustic Wave (SAW) filter are provided. The apparatus includes a calibration unit for outputting a detuning signal by which a resonance frequency of a Radio Frequency (RF) circuit is detuned with respect to a transmit operating frequency, and an RF unit for changing the resonance frequency according to the detuning signal and for outputting an out-of-band noise and a transmit signal having a relatively lower power than that of a case where the resonance frequency and the transmit operating frequency are tuned to each other.

Abstract: An Analog/Digital (A/D) modulation apparatus in a communication system supporting multiple communication modes and a method for controlling the same are provided. The A/D modulation apparatus includes an A/D modulation module having a structure in which a plurality of unit loops are extended by a serial connection, a control module configured to determine a modulation resolution needed for a communication mode to be used, a signal transfer control module including an input control module configured to transfer or block an intermediate output signal of a basic loop, as an input signal of an extended loop serially connected to the basic loop, in response to the modulation control bits provided from the control module, and an output module configured to generate a final digital-modulated signal based on a final output signal of the basic loop and a final output signal of the extended loop.

Abstract: An analog baseband filter apparatus for a multi-mode and multi-band wireless transceiver and a method for controlling the analog baseband filter apparatus are provided. The analog baseband filter apparatus includes a plurality of Radio Frequency (RF) units, each of the plurality of RF units being for receiving RF signals of one of a plurality of frequency bands and outputting baseband signals, a plurality of filter blocks for filtering and amplifying the baseband signals, and a switching unit for connecting at least two of the plurality of RF units to at least one of the plurality of filter blocks according to a selected communication mode, wherein the at least one of the plurality of filter blocks is configured to be connected to a capacitor region of an adjacent filter block from among the plurality of filter blocks.

Abstract: An apparatus and method of compensating for a direct voltage offset in a direct conversion receiver of a wireless communications system is provided.

Abstract: A method and an apparatus for calibration of a transmitter not having a Surface Acoustic Wave (SAW) filter are provided. The apparatus includes a calibration unit for outputting a detuning signal by which a resonance frequency of a Radio Frequency (RF) circuit is detuned with respect to a transmit operating frequency, and an RF unit for changing the resonance frequency according to the detuning signal and for outputting an out-of-band noise and a transmit signal having a relatively lower power than that of a case where the resonance frequency and the transmit operating frequency are tuned to each other.

Abstract: A drive amplifier having improved linearity while being characterized by low current consumption. The drive amplifier includes first and second transistors having a gate to which first and second differential Radio Frequency (RF) voltages are respectively input; a third transistor which has a drain connected to a drain of the second transistor and a source connected to the gate of the first transistor, and a drain-source current which increases with an increase in the second differential RF voltage; and a fourth transistor which has a drain connected to a drain of the first transistor and a source connected to the gate of the second transistor, and a drain-source current which increases with an increase in the first differential RF voltage.

Abstract: A method and an apparatus are provided for setting a cut-off frequency of an analog filter of a reception device for wireless communication. A deviation value is obtained that corresponds to an error between a first gain value based on an ideal transfer function curve and a second gain value based on a measured transfer function curve at an arbitrary frequency of a frequency band in which a constant interval is maintained between a slope of the ideal transfer function curve and a slope of the measured transfer function curve. A cut-off frequency that is used to measure the measured transfer function curve in a real environment, is corrected based on the obtained deviation value.

Abstract: A drive amplifier having improved linearity while being characterized by low current consumption. The drive amplifier includes first and second transistors having a gate to which first and second differential Radio Frequency (RF) voltages are respectively input; a third transistor which has a drain connected to a drain of the second transistor and a source connected to the gate of the first transistor, and a drain-source current which increases with an increase in the second differential RF voltage; and a fourth transistor which has a drain connected to a drain of the first transistor and a source connected to the gate of the second transistor, and a drain-source current which increases with an increase in the first differential RF voltage.

Abstract: An apparatus and method of compensating for a direct voltage offset in a direct conversion receiver of a wireless communications system is provided.

Abstract: A direct gate drive current reference source circuit is provided. The direct gate drive current reference source circuit includes a reference voltage generation core outputting a reference voltage of constant magnitude and a transistor directly receiving the reference voltage from the reference voltage generation core, without a resistor between the transistor and a ground.

Abstract: An Ultra Wide Band (UWB) transmitting and receiving device that includes a Digital Signal Processor (DSP) for implementing a DC offset cancellation algorithm, an adder for adding a baseband transmission signal from the transmitter and a calibration signal produced by the algorithm of the DSP, a modulator for modulating the signal from the adder, a transmitter amplifier for amplifying the modulated signal, a coupler for applying the output of the transmitter to the receiver, and a switch for selectively connecting the output of the coupler to the input of the receiver.

Abstract: An ultra wide band (UWB) pulse train generator, which includes a trigger signal controller for sequentially outputting n trigger signals for triggering generation of UWB pulse train in accordance with n bit data to be transmitted at a predetermined time period, a latch unit for loading in parallel the n bit data to be transmitted and sequentially toggling the loaded n bit data by one bit whenever the trigger signal is input from the trigger signal controller, and a pulse train generator for generating polarity pulses corresponding to a direction of an edge transition in accordance with toggling on each output signal of the latch unit.