Abstract:
An analog amplifier for recovering an abnormal operation of a common-mode feedback is provided. An analog variable amplifier includes a first input transistor and a second input transistor, a first output transistor and a second output transistor, a third transistor and a fourth transistor, a first current source, a fifth transistor and a sixth transistor, and a second current source. The first input transistor and the second input transistor amplify a bias current depending on a magnitude of a first input voltage and a second input voltage. The first output transistor and the second output transistor output the amplified bias current. The third transistor and the fourth transistor receive an output voltage of the first output transistor as an input and amplifying the received output voltage. The first current source provides a predetermined current between the first output transistor and the third transistor.
Abstract:
An analog amplifier is provided. The analog variable amplifier includes a first amplifier stage configured to amplify a bias current to output a first output voltage and a second output voltage that respectively depend on a magnitude of a first input voltage and a second input voltage, a second amplifier stage configured to receive the first output voltage and the second output voltage of the first amplifier stage as inputs and to amplify the received first output voltage and the second output voltage, and at least one auxiliary bias current source coupled to an electrical connection between the first amplifier stage and the second amplifier stage through which the second amplifier stage receives the first output voltage, and coupled to an electrical connection between the first amplifier stage and the second amplifier stage through which the second amplifier stage receives the second output voltage.
Abstract:
An analog baseband filter for a radio transceiver is provided. An analog baseband filter for a multi-mode multi-band radio transceiver includes a current-voltage conversion amplifier converting a current received at the analog baseband filter into a voltage and adjusting a gain of an output voltage of the current-voltage conversion amplifier using a plurality of resistors, and a source follower circuit compensating for temperature for the output voltage of the current-voltage conversion amplifier.
Abstract:
An analog amplifier for recovering an abnormal operation of a common-mode feedback is provided. An analog variable amplifier includes a first input transistor and a second input transistor, a first output transistor and a second output transistor, a third transistor and a fourth transistor, a first current source, a fifth transistor and a sixth transistor, and a second current source. The first input transistor and the second input transistor amplify a bias current depending on a magnitude of a first input voltage and a second input voltage. The first output transistor and the second output transistor output the amplified bias current. The third transistor and the fourth transistor receive an output voltage of the first output transistor as an input and amplifying the received output voltage. The first current source provides a predetermined current between the first output transistor and the third transistor.
Abstract:
An analog baseband filter for a radio transceiver is provided. An analog baseband filter for a multi-mode multi-band radio transceiver includes a current-voltage conversion amplifier converting a current received at the analog baseband filter into a voltage and adjusting a gain of an output voltage of the current-voltage conversion amplifier using a plurality of resistors, and a source follower circuit compensating for temperature for the output voltage of the current-voltage conversion amplifier.
Abstract:
An apparatus and a method for Direct Current (DC) offset calibration in a signal transmission device of a wireless communication system are provided. The apparatus includes a first DC calibration unit for removing a DC offset from a signal, which is output from a Current-to-Voltage Converter (IVC), by using a first DC calibration value, a Variable Gain Amplifier (VGA) for amplifying the signal output from the IVC, a second DC calibration unit for removing a DC offset from a signal output from the VGA by using a second DC calibration value, a Low Pass Filter (LPF) for filtering the signal output from the VGA, a third DC calibration unit for removing a DC offset from a signal output from the LPF by using a third DC calibration value, and a controller for determining the first DC calibration value, the second DC calibration value and the third DC calibration value.