AN AMPLIFIER FOR CONTINUOUS HIGH GAIN, NARROWBAND SIGNAL AMPLIFICATION

摘要

An apparatus and method to obtain a high Q, narrowband active filter with high gain suitable for an integrated circuit implementation. The high Q is achieved via active feedback with an amplitude control loop. The frequency control of the active filter is achieved by means of a frequency locked loop. Both control loops compare the thermal noise of the active filter itself to voltage and frequency references to achieve the stable operating point. Control loops are normally slow relative to the transmitted data, hence avoiding the data altering the operating point of the filter.