Methods and systems for down-converting a signal

摘要

Methods, systems, and apparatuses for down-converting a modulated carrier signal to a demodulated baseband signal by sampling a portion of the energy of the carrier signal are described herein. Briefly stated, such methods systems, and apparatuses operate by receiving a modulated carrier signal and using a control signal to control a switch or switches so as to transfer a portion of the energy from the modulated carrier signal in the form of charge to a storage capacitor during a plurality of aperture periods and to discharge the charge in the storage capacitor into a load during the time between the plurality of aperture periods. The demodulated baseband signal is generated—during both the charging and the discharging of the storage capacitor based on the energy accumulated at the storage capacitor as a net result of previous charging and discharging of the storage capacitor.

主权项

1. An apparatus that down-converts a modulated carrier signal to a demodulated baseband signal, comprising:
a receiver for receiving the modulated carrier signal, the modulated carrier signal modulated by at least one of an amplitude variation, a phase variation, a frequency variation, or a combination thereof; a switch which receives at an input the modulated carrier signal; a controller coupled to the switch, the controller providing a control signal comprised of a plurality of aperture periods, and the control signal controlling the switch so that the switch is closed during the plurality of aperture periods and opened outside of the plurality of aperture periods, and wherein:
a plurality of energy samples of energy in the modulated carrier signal are obtained by transferring a portion of energy from the modulated carrier signal to a storage capacitor by charging the storage capacitor each time the switch is closed by the control signal;each time the switch is opened by the control signal, discharging at the storage capacitor some of the energy previously transferred to the storage capacitor during previous aperture periods of the plurality of aperture periods, a remaining portion of the energy that is not discharged at the storage capacitor being accumulated with energy later transferred to the storage capacitor during later aperture periods of the plurality of aperture periods; andthe demodulated baseband signal is generated during both the charging and the discharging of the storage capacitor based on the energy accumulated at the storage capacitor as a net result of previous charging and discharging of the storage capacitor.