Abstract: The noise figure of a low noise amplifier (LNA) is reduced without sacrificing performance such as gain, IIP3, and wideband impedance matching. Embodiments include configuring a control module of the LNA to sum and scale an output from a current-sensing branch of the LNA and an output from a voltage sensing branch of the LNA into one or more summed and scaled outputs. The control module also feeds the one or more summed and scaled outputs back to at least one of the outputs of the branches of the LNA.

Abstract: The noise figure of a low noise amplifier (LNA) is reduced without sacrificing performance such as gain, IIP3, and wideband impedance matching. Embodiments include configuring a control module of the LNA to sum and scale an output from a current-sensing branch of the LNA and an output from a voltage sensing branch of the LNA into one or more summed and scaled outputs. The control module also feeds the one or more summed and scaled outputs back to at least one of the outputs of the branches of the LNA.

Abstract: An automatic frequency calibration circuit and an automatic frequency calibration method for a fractional-N frequency synthesizer are provided. In a calibration mode, a state machine adjusts a fractional part and an integer part of a division ratio of a frequency divider unit according to a required precision. A first and a second frequency detecting units detect a reference frequency and an output frequency of the frequency divider unit, respectively. A judging interval unit defines at least one judging period in a total comparison time. A comparator compares the outputs of the first and the second frequency detecting units and outputs a comparison result at the judging period. Wherein, the state machine changes the capacitor configuration of a voltage-controlled oscillator when the comparison result shows that the reference frequency does not match the output frequency of the frequency divider unit.

Abstract: An automatic frequency calibration circuit and an automatic frequency calibration method for a fractional-N frequency synthesizer are provided. In a calibration mode, a state machine adjusts a fractional part and an integer part of a division ratio of a frequency divider unit according to a required precision. A first and a second frequency detecting units detect a reference frequency and an output frequency of the frequency divider unit, respectively. A judging interval unit defines at least one judging period in a total comparison time. A comparator compares the outputs of the first and the second frequency detecting units and outputs a comparison result at the judging period. Wherein, the state machine changes the capacitor configuration of a voltage-controlled oscillator when the comparison result shows that the reference frequency does not match the output frequency of the frequency divider unit.