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 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:
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:
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.