Abstract:
A mixer includes a transformer and a mixing circuit. The transformer is employed for receiving an input signal to generate a differential output. The mixing circuit is coupled to the transformer, and employed for mixing the differential output with N oscillating signals having different phases to generate a plurality of mixed output signals, wherein N is greater than 2.
Abstract:
An adjusting method for reducing local oscillation leakage or I/Q mismatch in a receiver includes the steps of: (a) detecting a current extent of local oscillation leakage or I/Q mismatch; (b) determining if an adjusting direction is correct with reference to the current extent of local oscillation leakage or I/Q mismatch thus detected, maintaining the adjusting direction if correct, and reversing the adjusting direction upon determining that the adjusting direction is incorrect; and (c) adjusting a control signal according to the adjusting direction.
Abstract:
A clock generator is provided, capable of automatically adjusting an output clock when process, voltage, or temperature variation occurs. The clock generator includes a current generator, for generating a first current and a second current according to a bias signal, an oscillator, coupled to the current generator, for generating a clock signal according to the first current, a frequency detector, coupled to the oscillator, for generating a control signal according to the clock signal and a reference signal, and a bias voltage adjuster, coupled to the current generator and the frequency detector, for adjusting the bias signal according to the control signal. When the signal frequency of the clock signal changes, the bias signal corresponds to the bias voltage adjuster, to adjust the first current and the second current.
Abstract:
An adjusting method for reducing local oscillation leakage or I/Q mismatch in a receiver includes the steps of: (a) detecting a current extent of local oscillation leakage or I/Q mismatch; (b) determining if an adjusting direction is correct with reference to the current extent of local oscillation leakage or I/Q mismatch thus detected, maintaining the adjusting direction if correct, and reversing the adjusting direction upon determining that the adjusting direction is incorrect; and (c) adjusting a control signal according to the adjusting direction.
Abstract:
Disclosed is a mixer comprising: a switching circuit, having a first pair of differential signal nodes and a second pair of differential signal nodes, for switching according to a local oscillation signal; an amplifying stage circuit, for receiving an input signal and amplifying the input signal; a load circuit, for serving as the loading of the mixer and generating an output signal of the mixer; a common-mode feedback circuit, for receiving the output signal and generating a feedback signal according to the output signal; a first current source, for receiving the feedback signal and generating a first current according to the feedback signal; and a second current source, for receiving the feedback signal and generating a second current according to the feedback signal.
Abstract:
A method and device for calibrating in-phase and quadrature-phase (IQ) mismatch. The device is used in a direct down-conversion circuit of a communication system. The device has a first mixer for mixing an RF signal with a first carrier signal, so as to generate an in-phase analog signal; a second mixer for mixing the RF signal with a second carrier signal, so as to generate a quadrature-phase analog signal; an operation unit for executing a Least Mean Square (LMS) algorithm and thereby generating a compensation signal according to the in-phase analog signal and the quadrature-phase analog signal; and a calibration unit for compensating the in-phase analog signal and the quadrature-phase analog signal according to the compensation signal, so as to calibrate the IQ mismatch between the in-phase analog signal and the quadrature-phase analog signal.
Abstract:
A mixer capable of detecting or controlling a common mode voltage thereof, includes at least: a mixing module for mixing a first set of differential signals and a second set of differential signals to generate at least one mixed signal; and a compensation module for compensating at least one operation point of the mixing module.
Abstract:
A mixer capable of detecting or controlling a common mode voltage thereof, includes at least: a mixing module for mixing a first set of differential signals and a second set of differential signals to generate at least one mixed signal; and a compensation module for compensating at least one operation point of the mixing module.
Abstract:
A signal amplifying circuit includes: an input stage circuit, arranged to receive an input signal; a first inductive device coupled between the input stage circuit and a first reference voltage; an output stage circuit arranged to generate an output signal according to the input signal; and a second inductive device coupled between the output stage circuit and a second reference voltage, wherein at least a part of a winding of the first inductive element is cross-coupled to at least a part of a winding of the second inductive element.
Abstract:
The invention discloses a voltage regulating apparatus, which includes: a linear regulator generating a first error signal; a switching regulator generating a first and a second PWM signals; a selecting unit coupled to the linear and switching regulators, receiving the first error signal and the second PWM signal, and outputting a regulating signal; a first power transistor coupled to the switching regulator and receiving the first PWM signal; and a second power transistor coupled to the selecting unit and receiving the regulating signal; wherein the voltage regulating apparatus can be put either in a linear mode of operation if the first error signal is selected as the regulating signal, or in a switching mode of operation if the second PWM signal is selected as the regulating signal.