Electronic envelope detection circuit and corresponding demodulator
AssigneeSTMicroelectronics S.r.l.
InventorLionel Vogt
Life of this patent
Estimating the term…
Abstract
An electronic envelope detection circuit includes an input signal detecting circuit having at least one MOS transistor configured to receive a radiofrequency input signal and to deliver an internal signal on the basis of the input signal. The biasing point of the at least one transistor is controlled by the input signal and a control signal. A processing circuit that is coupled to the input signal detecting circuit is configured to deliver a low-frequency output signal on the basis of the internal signal and further deliver the control signal on the basis of the output signal. In operation, the value of the control signal decreases when the average power of the input signal increases, and vice versa.
Claims35
An electronic envelope detection circuit, comprising:
- a transformer comprising an input winding configured to receive a radiofrequency input signal, a first output winding and a second output winding;
- a first MOS transistor and a second MOS transistor wherein drains of the first and second MOS transistors are coupled to generate an internal signal, gates of the first and second MOS transistors are coupled to terminals of the first output winding, and sources of the first and second MOS transistors are coupled to terminals of the second output winding;
- a resistor-capacitor circuit having an input coupled to receive the internal signal and an output configured to generate a control signal applied to a center tap of the first output winding;
- and
- an output transistor having a gate coupled to receive the internal signal and a drain configured to generate an output signal.
An electronic envelope detection circuit, comprising:
- a transformer comprising an input winding having a first terminal configured to receive a radiofrequency input signal and an output winding;
- an input MOS transistor having a drain configured to generate an internal signal, a gate coupled to a first terminal of the output winding, and a source coupled to the first terminal of the input winding;
- a resistor-capacitor circuit having an input coupled to receive the internal signal and an output configured to generate a control signal applied to a second terminal of the output winding;
- and
- an output transistor having a gate coupled to receive the internal signal and a drain configured to generate an output signal.
An electronic envelope detection circuit, comprising:
- a first MOS transistor and a second MOS transistor wherein drains of the first and second MOS transistors are coupled to generate an internal signal, gates of the first and second MOS transistors are coupled to receive an input radiofrequency signal in differential mode, and sources of the first and second MOS transistors are coupled to a reference voltage node;
- a control circuit configured to generate first and second control signals from the internal signal, wherein the first control signal is applied to the gate of the first MOS transistor and wherein the second control signal is applied to the gate of the second MOS transistor;
- and
- an output transistor having a gate coupled to receive the internal signal and a drain configured to generate an output signal.
Dependencies are inferred from the claim text.