Abstract: A gain control circuit of the wireless receiver comprises a plurality of stages-amplifier, an analog gain control circuit, and a digital gain control circuit, wherein the analog gain control circuit generates an analog controlling voltage for regulating the gain of the post-amplifier by an analog gain controlling process, and the digital gain control circuit is used for determining a plurality of gain curves for the pre-amplifier, and the gain curves are all operating between the first default voltage and second default voltage. While the analog controlling voltage is over the first default voltage or second default voltage, the gain curve will be switched, thereby, the analog gain controlling process can be with the digital gain controlling process therein for improving the linearity of the gain regulation and reducing the transient response during the gain switching process.

Abstract: A gain control circuit of the wireless receiver comprises a plurality of stages-amplifier, an analog gain control circuit, and a digital gain control circuit, wherein the analog gain control circuit generates an analog controlling voltage for regulating the gain of the post-amplifier by an analog gain controlling process, and the digital gain control circuit is used for determining a plurality of gain curves for the pre-amplifier, and the gain curves are all operating between the first default voltage and second default voltage. While the analog controlling voltage is over the first default voltage or second default voltage, the gain curve will be switched, thereby, the analog gain controlling process can be with the digital gain controlling process therein for improving the linearity of the gain regulation and reducing the transient response during the gain switching process.

Abstract: A method for automatic frequency tuning in a phase lock loop suitable for use in multi-band VCO wireless systems having very limited initial frequency lock times is disclosed. A predetermined subset of VCOs out of a larger bank of VCOs is selected to serve as interpolation points. The interpolation point VCOs are pre-calibrated with a predetermined voltage and the resultingly generated frequency for each of the interpolation point VCOs is stored into memory as a (frequency, VCO) pair, one pair for each interpolation point VCO. When a desired frequency then is given to the system, an appropriate VCO is selected by interpolation using the (frequency, VCO) pairs of the two most adjacent interpolation points for tracking and locking.

Abstract: A method for automatic frequency tuning in a phase lock loop suitable for use in multi-band VCO wireless systems having very limited initial frequency lock times is disclosed. A predetermined subset of VCOs out of a larger bank of VCOs is selected to serve as interpolation points. The interpolation point VCOs are pre-calibrated with a predetermined voltage and the resultingly generated frequency for each of the interpolation point VCOs is stored into memory as a (frequency, VCO) pair, one pair for each interpolation point VCO. When a desired frequency then is given to the system, an appropriate VCO is selected by interpolation using the (frequency, VCO) pairs of the two most adjacent interpolation points for tracking and locking.

Abstract: A PLL includes a loop filter for accumulating charge to generate a loop-filter voltage and a VCO having a plurality of frequency ranges. The VCO receives the loop-filter voltage and generates an output signal having a frequency according to the loop-filter voltage and a currently selected VCO frequency range. During PLL calibration, the loop-filter is connected to a constant voltage source; the PLL feedback signal is synchronized with the reference signal; a linear search, a binary search, or a memory lookup is used to find a first and a second VCO frequency range; first and second time durations are measured for the time durations between the second rising edges of the reference signal and the PLL feedback signal for the two VCO frequency ranges, and the optimal VCO frequency range is determined by setting the VCO frequency range to be the VCO frequency range having the shortest measured time duration.

Abstract: A phase calibrating apparatus applied in a mixer includes a signal generator outputting a first signal and a second signal. The first signal has a phase differing by a phase value from the second signal. The phase calibrating apparatus is used to adjust the phase value to a predetermined value. The phase calibrating apparatus includes a multiplication unit and a comparator/controller unit. The multiplication unit has a multiplication of the first signal and the second signal to output a DC value corresponding to the phase value. The comparator/controller unit compares the DC value with a reference value and outputs a control signal. The signal generator adjusts the phase value according to the control signal until the phase value is substantially equal to the predetermined value.

Abstract: A PLL includes a loop filter for accumulating charge to generate a loop-filter voltage and a VCO having a plurality of frequency ranges. The VCO receives the loop-filter voltage and generates an output signal having a frequency according to the loop-filter voltage and a currently selected VCO frequency range. During PLL calibration, the loop-filter is connected to a constant voltage source; the PLL feedback signal is synchronized with the reference signal; a linear search, a binary search, or a memory lookup is used to find a first and a second VCO frequency range; first and second time durations are measured for the time durations between the second rising edges of the reference signal and the PLL feedback signal for the two VCO frequency ranges, and the optimal VCO frequency range is determined by setting the VCO frequency range to be the VCO frequency range having the shortest measured time duration.