Patent ID: 8339194

Claim:
A demodulator, comprising: a rectification circuit comprising: a DC block, a first resistor, a MOSFET; a current source and a second resistor, wherein an end of the DC block is configured to receive an ASK signal, another end of the DC block is connected to an end of the first resistor and a gate of the MOSFET, another end of the first resistor is configured to receive a bias voltage, the current source and the second resistor are in a parallel connection and further connected to a drain of the MOSFET so as to form a series connection, the formed series connection is set between a positive voltage source and a ground; a filter connected to the common terminal and configured to receive a drain signal generated on the common terminal, remove carriers from the drain signal to generate a filtered signal; and a decision circuit connected to an output end of the filter and configured to receive the filtered signal and use the filtered signal to generate a base band signal.