Abstract: An apparatus and a method for removing RX DC in a wireless communication system are provided. A receiver apparatus includes a local oscillator, a mixer for converting a received signal to a baseband signal using a frequency provided from the local oscillator, and a DC compensator, comprising an operational amplifier and a low pass filter, for compensating DC in an output signal of a frequency converter by adjusting a pass band size of the low pass filter.

Abstract: An antenna device for a portable terminal, which allows a whip antenna and helical antenna of a terminal to be retracted and withdrawn along an extension from the terminal, while not causing them to protrude out of the terminal. The antenna device provided with a whip antenna and helical antenna further includes an antenna housing disposed at a desired position in the main body, which permits the whip antenna to be retracted and withdrawn through the helical antenna, while causing the helical antenna to be withdrawn along an extension from the main body at the same time, and permits the helical antenna to be retracted, so that it can be inserted into the main body; and a housing coupling portion disposed in the main body for supporting the antenna housing.

Abstract: An apparatus for compensating for a phase mismatch in a Quadrature Phase Shift Keying (QPSK) demodulator that includes a phase mismatch extractor module for generating a signal including a phase mismatch function by mixing an I-channel demodulation signal and a Q-channel demodulation signal, which are output signals of a phase shifter, and extracting the phase mismatch function by filtering the generated signal; and a phase mismatch compensator module for digital-converting the phase mismatch function, mapping the digital-converted phase mismatch function to a first compensation signal, generating a second compensation signal by mixing the digital-converted phase mismatch function with a baseband I-channel signal, generating a third compensation signal by adding a baseband Q-channel signal to the second compensation signal, and mixing the first compensation signal with the third compensation signal.

Abstract: Disclosed is a combined DMB and mobile communication antenna apparatus for a mobile communication terminal. The antenna apparatus includes one whip antenna for receiving both signals in a DMB frequency band and in a mobile communication frequency band, a first contact coupled to the whip antenna to receive the signal in the mobile communication frequency band from the whip antenna, and a second contact located under the first contact within a terminal main body and coming in contact with the whip antenna at a lower end of the whip antenna to receive the signal in the DMB frequency band when the whip antenna is drawn out.

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 antenna device for a portable terminal, which allows a whip antenna and helical antenna of a terminal to be retracted and withdrawn along an extension from the terminal, while not causing them to protrude out of the terminal. The antenna device provided with a whip antenna and helical antenna further includes an antenna housing disposed at a desired position in the main body, which permits the whip antenna to be retracted and withdrawn through the helical antenna, while causing the helical antenna to be withdrawn along an extension from the main body at the same time, and permits the helical antenna to be retracted, so that it can be inserted into the main body; and a housing coupling portion disposed in the main body for supporting the antenna housing.

Abstract: An apparatus for compensating for a phase mismatch in a Quadrature Phase Shift Keying (QPSK) demodulator that includes a phase mismatch extractor module for generating a signal including a phase mismatch function by mixing an I-channel demodulation signal and a Q-channel demodulation signal, which are output signals of a phase shifter, and extracting the phase mismatch function by filtering the generated signal; and a phase mismatch compensator module for digital-converting the phase mismatch function, mapping the digital-converted phase mismatch function to a first compensation signal, generating a second compensation signal by mixing the digital-converted phase mismatch function with a baseband I-channel signal, generating a third compensation signal by adding a baseband Q-channel signal to the second compensation signal, and mixing the first compensation signal with the third compensation signal.

Abstract: Disclosed is a combined DMB and mobile communication antenna apparatus for a mobile communication terminal. The antenna apparatus includes one whip antenna for receiving both signals in a DMB frequency band and in a mobile communication frequency band, a first contact coupled to the whip antenna to receive the signal in the mobile communication frequency band from the whip antenna, and a second contact located under the first contact within a terminal main body and coming in contact with the whip antenna at a lower end of the whip antenna to receive the signal in the DMB frequency band when the whip antenna is drawn out.

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.