摘要:
Embodiments of the invention provide techniques for calibrating voltage-controlled oscillators (VCOs). Multiple VCOs may be disposed on a chip with the VCOs having different frequency ranges. The VCOs may be selected and tested to determine a desired VCO to use to tune to a selected channel frequency. Each of the VCOs has multiple possible varactor configurations. The varactor configurations of the desired VCO determined to be used to tune to the selected channel frequency can be selected and tested to determine a desired varactor configuration for the desired VCO. The desired VCO with the desired varactor configuration will preferably be able to produce a full range of desired frequencies corresponding to all channel frequencies desired.
摘要:
Embodiments of the invention provide techniques for calibrating voltage-controlled oscillators (VCOs). Multiple VCOs may be disposed on a chip with the VCOs having different frequency ranges. The VCOs may be selected and tested to determine a desired VCO to use to tune to a selected channel frequency. Each of the VCOs has multiple possible varactor configurations. The varactor configurations of the desired VCO determined to be used to tune to the selected channel frequency can be selected and tested to determine a desired varactor configuration for the desired VCO. The desired VCO with the desired varactor configuration will preferably be able to produce a full range of desired frequencies corresponding to all channel frequencies desired.
摘要:
A receiver circuit comprising a quadrature passive mixer having an input and an output, and an input impedance of the quadrature passive mixer provides a band-pass response. One or more output impedances coupled to the output of the quadrature passive mixer. A low noise amplifier (LNA) having an input and an output coupled to the quadrature passive mixer, the LNA configured to provide substantially linear transconductance over a predetermined input range.
摘要:
A receiver circuit includes a quadrature passive mixer, a first charge load, and a second charge load. The quadrature passive mixer has a differential input for receiving a differential input signal, and arranged for mixing the differential input signal with a quadrature local oscillator (LO) signal. The quadrature passive mixer has an in-phase mixer with a differential in-phase output, and a quadrature-phase mixer with a differential quadrature-phase output. The first and second charge loads are coupled to differential in-phase output and differential quadrature-phase output, respectively. In every quarter cycle of the quadrature LO signal, the differential in-phase output and the differential quadrature-phase output are arranged to be not shorted so as to avoid charging sharing between the first charge load and the second charge load, or are arranged to be shorted to cause charging sharing between the first charge load and the second charge load that generates a leakage path.
摘要:
A receiver circuit comprising a quadrature passive mixer having an input and an output, and an input impedance of the quadrature passive mixer provides a band-pass response. One or more output impedances coupled to the output of the quadrature passive mixer. A low noise amplifier (LNA) having an input and an output coupled to the quadrature passive mixer, the LNA configured to provide substantially linear transconductance over a predetermined input range.
摘要:
A receiver circuit includes a quadrature passive mixer, a first charge load, and a second charge load. The quadrature passive mixer has a differential input for receiving a differential input signal, and arranged for mixing the differential input signal with a quadrature local oscillator (LO) signal. The quadrature passive mixer has an in-phase mixer with a differential in-phase output, and a quadrature-phase mixer with a differential quadrature-phase output. The first and second charge loads are coupled to differential in-phase output and differential quadrature-phase output, respectively. In every quarter cycle of the quadrature LO signal, the differential in-phase output and the differential quadrature-phase output are arranged to be not shorted so as to avoid charging sharing between the first charge load and the second charge load, or are arranged to be shorted to cause charging sharing between the first charge load and the second charge load that generates a leakage path.
摘要:
A receiver circuit includes an amplifier, an output impedance, and a mixer. The amplifier is arranged to generate an amplifier output. The mixer has an input and an output respectively coupled to the amplifier and the output impedance. The output impedance sets frequency selectivity provided at the input of the mixer, and the mixer is arranged to down-convert a signal derived from the amplifier output and accordingly generate a down-converted signal at the output of the mixer for further signal processing.
摘要:
A method and apparatus are provided for generating first and second modulation signals from a local oscillator signal for quadrature subharmonic modulation of a quadrature amplitude modulated information signal. The method includes the steps of delaying the local oscillator signal in a plurality of incremental odd and even delay steps to form respective sets of odd and even modulator signals, said odd set of modulator signals together forming the first modulation signal and said even set forming the second modulation signal for quadrature subharmonic modulation of the quadrature amplitude modulated information signal and controlling a magnitude of the incremental delays based upon a predetermined phase offset between the local oscillator signal and a last delay step of the incremental delay steps.
摘要:
A receiver circuit includes an amplifier, an output impedance, and a mixer. The amplifier is arranged to generate an amplifier output. The mixer has an input and an output respectively coupled to the amplifier and the output impedance. The output impedance sets frequency selectivity provided at the input of the mixer, and the mixer is arranged to down-convert a signal derived from the amplifier output and accordingly generate a down-converted signal at the output of the mixer for further signal processing.
摘要:
A quadrature mixer with an LO input is provided. The quadrature mixer receives a signal having a frequency FLO and a signal input having a frequency FSIG, and has an output that comprises an output impedance that is high at frequencies of |FLO−FSIG | and |FLO+FSIG| and low at other. A mixer coupled to the output impedance interacts with the output impedance such that an impedance presented at the signal input is high for signals at FSIG if FSIG is a predetermined signal frequency, and low at other frequencies.