Abstract: A signal transceiver includes a first power amplifier coupled to a chip output port of a chip; an impedance transforming circuit; a switching circuit arranged to selectively couple the chip output port to a first port of the impedance transforming circuit; and a receiving amplifier coupled to a second port of the impedance transforming circuit.

Abstract: A calibration apparatus includes: a first circuit arranged for generating a reference voltage with respect to a first circuit element according to a reference current flowing to the first circuit element; a second circuit arranged for generating an output voltage according to a tunable current; and an adjusting circuit for adjusting the tunable current to a target current value according to the reference voltage and the output voltage, wherein the adjusting circuit comprises: a search unit for performing a search according to a comparison result of the reference voltage and the output voltage to thereby determine a control setting; and a control unit coupled to the search unit, and for generating a control signal to the second circuit according to the control setting, and after the search unit adjusts the control setting, the search unit stops adjusting the control setting according to the comparison result.

Abstract: A radio-frequency receiver. The radio-frequency receiver includes a first and second low noise amplifier (LNA), a local oscillating module, and a first, second, and third mixer. The first LNA amplifies a first RF signal. The local oscillating module generates a first, second and third local oscillating signals. The first local oscillating signal is generated according to the second local oscillating signal. The first mixer mixes the first RF signal with the first local oscillating signal to generate an intermediate frequency signal. The second LNA amplifies a second RF signal. The second and third mixers can be operated in two modes. The second and third mixers mix the intermediate frequency signal to generate a first and second baseband signal respectively in the first mode, and the second and third mixers mix the second RF signal with the second and third oscillating frequency respectively in a second mode.

Abstract: A calibration apparatus includes: a first circuit arranged for generating a reference voltage with respect to a first circuit element according to a reference current flowing to the first circuit element, a second circuit arranged for generating an output voltage according to a tunable current, and an adjusting circuit coupled to the first circuit and the second circuit for adjusting the tunable current to a target current value according to the reference voltage and the output voltage.

Abstract: A mixer is provided. The transconductance stage receives an input signal through an input node and outputs an output signal through an output node. The transconductance stage includes a first transistor coupled between the output node and a first power node, having a first gate coupled to the input node, and operating in a saturation region, a second transistor coupled to the first power node, having a second gate coupled to the input node, and operating in a sub-threshold region, a first biasing circuit providing a first bias voltage, and a third transistor coupled between the output node and the second transistor, and having a third gate coupled to the first bias voltage. The switching quad is coupled to the output node and generates a translation current according to the output signal. The transimpedance amplifier transforms the translation current to a corresponding voltage.

Abstract: The present invention discloses a circuit for settling DC offset and controlling RC time-constant in a direct conversion receiver. The circuit includes a variable resistive unit for providing a continuously or non-continuously variable resistance in the direct conversion receiver. The variable resistive unit can provide the variable resistance by utilizing a controllable transistor or a plurality of resistors. Accordingly, the variable resistive unit can be coupled to a capacitor for constituting a high pass filter, which is capable of rapidly settling DC offset in a direct conversion receiver.

Abstract: A receiving device includes: a mixer module arranged to receive an input signal to generate a down-converted output; a first active filter, the first active filter arranged to receive the down-converted output and perform an active filtering process upon the down-converted output to generate a first filtered output; a passive filter, the passive filter arranged to receive the first filtered output and perform a passive filtering process upon the first filtered output to generate a second filtered output; and a processing circuit, the processing circuit arranged to receive the second filtered output and process the second filtered output to generate an output signal corresponding to the input signal.

Abstract: A mixer is provided. The transconductance stage receives an input signal through an input node and outputs an output signal through an output node. The transconductance stage includes a first transistor coupled between the output node and a first power node, having a first gate coupled to the input node, and operating in a saturation region, a second transistor coupled to the first power node, having a second gate coupled to the input node, and operating in a sub-threshold region, a first biasing circuit providing a first bias voltage, and a third transistor coupled between the output node and the second transistor, and having a third gate coupled to the first bias voltage. The switching quad is coupled to the output node and generates a translation current according to the output signal. The transimpedance amplifier transforms the translation current to a corresponding voltage.

Abstract: A calibration apparatus includes: a first circuit arranged for generating a reference voltage with respect to a first circuit element according to a reference current flowing to the first circuit element, a second circuit arranged for generating an output voltage according to a tunable current, and an adjusting circuit coupled to the first circuit and the second circuit for adjusting the tunable current to a target current value according to the reference voltage and the output voltage.

Abstract: The present invention sets forth a controllable resistive circuit which comprises a transistor, a capacitor, a charging unit and a discharging unit. The transistor is capable of providing a variable resistance which is controlled to vary continuously and smoothly. The charging and discharging units are used to respectively charge and discharge the capacitor in different periods. As a result, the capacitor can provide a variable voltage which is controlled to vary continuously and smoothly to control the equivalent resistance of the transistor during the period the capacitor is discharging. Therefore, the controllable resistive circuit in accordance with the present invention is capable of being used in any kind of circuit which requires a variable resistance varied continuously and smoothly.

Abstract: An amplifier includes an amplifier module coupled to an input node, and an attenuating module. The attenuating module includes an attenuation resistor coupled to the input node, and an impedance compensation module coupled to the input node. The impedance compensation module compensates an input impedance when an input RF signal is attenuated by the attenuating module.

Abstract: A mixer is provided. The mixer comprises a Gilbert cell mixer core, a pair of load devices, a transconductor cell, and a current injection branch. The Gilbert cell mixer core has first and second nodes, receives a first differential input signal, and provides a differential output signal at the first nodes. The load devices are respectively coupled between the first nodes of the Gilbert cell mixer core and a first fixed voltage. The transconductor cell is coupled between the second nodes and a second fixed voltage and receives a second differential input signal. The dynamic current injection branch comprises first and second pairs of MOS transistors each connected in parallel and having drains commonly coupled to a corresponding second node and gates receiving a third differential input signal. There is a phase difference of 90° between the first and third differential input signals.

Abstract: A method for executing a mouse function of electronic device and an electronic device thereof are provided. In the present method, an amount and a relative position of input signals are detected by a sensor module. Then, whether the amount and the relative position are respectively conformed to a predetermined value is determined. If the predetermined values are conformed, whether the input signal is conformed to a specific signal is determined when a variation of the relative position is occurred. Finally, a corresponding mouse function is executed according to a type of the variation if the variation is conformed to the specific signal. As a result, a mouse device is no longer needed for a user to accomplish a directional operation on the electronic device so as to prevent inconvenience of particularly carrying a mouse device.

Abstract: The present invention discloses a circuit for settling DC offset and controlling RC time-constant in a direct conversion receiver. The circuit includes a variable resistive unit for providing a continuously or non-continuously variable resistance in the direct conversion receiver. The variable resistive unit can provide the variable resistance by utilizing a controllable transistor or a plurality of resistors. Accordingly, the variable resistive unit can be coupled to a capacitor for constituting a high pass filter, which is capable of rapidly settling DC offset in a direct conversion receiver.

Abstract: An amplifier includes an amplifier module coupled to an input node, and an attenuating module. The attenuating module includes an attenuation resistor coupled to the input node, and an impedance compensation module coupled to the input node. The impedance compensation module compensates an input impedance when an input RF signal is attenuated by the attenuating module.

Abstract: An apparatus, an integrated circuit, and a method of compensating I/Q (inphase/quadrature) phase mismatch. The apparatus comprises a mixer, a phase detector, and a calibration controller. The mixer mixes an inphase calibration signal with an inphase component of a local oscillation signal to generate a first signal, mixes a quadrature calibration signal with a quadrature component of the local oscillation signal to generate a second signal, and mixes an incoming RF signal with the local oscillation signal to demodulate the incoming RF signal. The phase detector coupled to the mixer, determines a phase difference between the first and second signals. The calibration controller coupled to the phase detector, adjusts phases of the inphase and quadrature calibration signals such that the phase difference is substantially 90 degrees.

Abstract: A radio-frequency receiver. The radio-frequency receiver includes a first and second low noise amplifier (LNA), a local oscillating module, and a first, second, and third mixer. The first LNA amplifies a first RF signal. The local oscillating module generates a first, second and third local oscillating signals. The first local oscillating signal is generated according to the second local oscillating signal. The first mixer mixes the first RF signal with the first local oscillating signal to generate an intermediate frequency signal. The second LNA amplifies a second RF signal. The second and third mixers can be operated in two modes. The second and third mixers mix the intermediate frequency signal to generate a first and second baseband signal respectively in the first mode, and the second and third mixers mix the second RF signal with the second and third oscillating frequency respectively in a second mode.

Abstract: A radio-frequency receiver. The radio-frequency receiver includes a first and second low noise amplifier (LNA), a local oscillating module, and a first, second, and third mixer. The first LNA amplifies a first RF signal. The local oscillating module generates a first, second and third local oscillating signals. The first local oscillating signal is generated according to the second local oscillating signal. The first mixer mixes the first RF signal with the first local oscillating signal to generate an intermediate frequency signal. The second LNA amplifies a second RF signal. The second and third mixers can be operated in two modes. The second and third mixers mix the intermediate frequency signal to generate a first and second baseband signal respectively in the first mode, and the second and third mixers mix the second RF signal with the second and third oscillating frequency respectively in a second mode.

Abstract: The present invention sets forth a controllable resistive circuit which comprises a transistor, a capacitor, a charging unit and a discharging unit. The transistor is capable of providing a variable resistance which is controlled to vary continuously and smoothly. The charging and discharging units are used to respectively charge and discharge the capacitor in different periods. As a result, the capacitor can provide a variable voltage which is controlled to vary continuously and smoothly to control the equivalent resistance of the transistor during the period the capacitor is discharging. Therefore, the controllable resistive circuit in accordance with the present invention is capable of being used in any kind of circuit which requires a variable resistance varied continuously and smoothly.

Abstract: A radio-frequency receiver. The radio-frequency receiver includes a first and second low noise amplifier (LNA), a local oscillating module, and a first, second, and third mixer. The first LNA amplifies a first RF signal. The local oscillating module generates a first, second and third local oscillating signals. The first local oscillating signal is generated according to the second local oscillating signal. The first mixer mixes the first RF signal with the first local oscillating signal to generate an intermediate frequency signal. The second LNA amplifies a second RF signal. The second and third mixers can be operated in two modes. The second and third mixers mix the intermediate frequency signal to generate a first and second baseband signal respectively in the first mode, and the second and third mixers mix the second RF signal with the second and third oscillating frequency respectively in a second mode.