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US 6,606,025 B1Granted
Synchronous demodulator
AssigneeMotorola, Inc.
InventorsHans Staufer, Anthony Newton
Life of this patent
Estimating the term…
Abstract
A synchronous demodulator (10) drives an output antenna (21) with a push-pull driver circuit (13). The push-pull driver circuit (13) includes two transistors connected in a push-pull configuration driving a center-tapped transformer (17). The transformer (17) couples the push-pull driver circuit (13) to an antenna (21). Received signals are demodulated in the output driver circuit (13).
Claims6
A synchronous demodulator comprising:
- an output driver stage having a power supply input;
- and
- a coupling transformer having one inductor of the coupling transformer operably coupled in series between the power supply input and a power supply terminal of the synchronous demodulator for detecting variation in a load current of the output driver stage;
- wherein the output driver stage includes;
- a push-pull output driver having a first transistor and a second transistor;
- a center-tapped transformer wherein the first transistor drives one terminal of a center-tapped winding, and the second transistor drives a second terminal of the center-tapped winding;
- a first inductor coupled in series with the power supply input;
- and
- a second inductor operably coupled to develop a voltage selectively in response to current flow through the fast inductor corresponding to a sub-carrier of a received signal derived by modulating the signal of said output driver stage with said sub-carrier.
6 more elements
A synchronous demodulator comprising:
- an output driver stage having a power supply input;
- a coupling transformer having one inductor of the coupling transformer operably coupled in series between the power supply input and a power supply terminal of the synchronous demodulator for detecting variation in a load current of the output driver stage, and
- an antenna coupled to the output driver stage
- said variation in load current corresponding to a sub-carrier of a received signal derived by modulating the signal of said output driver stage with said sub-carrier.
1 more element
Dependencies are inferred from the claim text.