Envelope detector with clamping circuitry
AssigneeQUALCOMM Incorporated
InventorsCheng Tan, Bruce Charles Fischer, Jr., Brian French
Life of this patent
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Abstract
An envelope detection circuit and methods for detecting an envelope of a signal using such an envelope detection circuit. One example envelope detection circuit generally includes a first diode, a capacitive element, and a clamping circuit. The first diode has an anode coupled to an input node of the envelope detection circuit and has a cathode coupled to an output node of the envelope detection circuit. The capacitive element is coupled in shunt between the output node and a reference potential node, and the clamping circuit is coupled in shunt between the input node and the reference potential node. The clamping circuit generally includes a resistive element coupled in series with a second diode.
Claims15
An envelope detection circuit comprising:
- a first diode having an anode coupled to an input node of the envelope detection circuit and having a cathode coupled to an output node of the envelope detection circuit;
- a first capacitive element coupled in shunt between the output node and a reference potential node;
- a clamping circuit coupled in shunt between the input node and the reference potential node, wherein the clamping circuit comprises a first resistive element coupled in series with a second diode;
- and
- an impedance matching circuit coupled between the input node of the envelope detection circuit and the anode of the first diode, wherein the impedance matching circuit comprises:
- a second capacitive element coupled in series between the input node of the envelope detection circuit and the anode of the first diode;
- and
- an inductive element coupled in shunt between the anode of the first diode and the reference potential node.
A method for envelope detection, comprising:
- detecting an envelope of a signal using a first diode and a first capacitive element coupled in shunt to a cathode of the first diode;
- clamping the signal using a clamping circuit comprising a first resistive element coupled in series with a second diode;
- and
- transforming an impedance using an impedance matching circuit coupled to an anode of the first diode, wherein the impedance matching circuit comprises:
- a second capacitive element coupled in series with the anode of the first diode;
- and
- an inductive element coupled in shunt to the anode of the first diode.
A method for envelope detection, comprising:
- detecting an envelope of a signal using a first diode and a capacitive element coupled in shunt to a cathode of the first diode;
- clamping the signal using a clamping circuit comprising a resistive element coupled in series with a second diode;
- DC biasing an anode of the first diode using a first DC bias circuit;
- and
- DC biasing the clamping circuit using a second DC bias circuit, wherein the second DC bias circuit has the same components and topology as the first DC bias circuit.
Dependencies are inferred from the claim text.