Reduced current antenna circuit
AssigneeTexas Instruments Deutschland GmbH
InventorMichael Knebelkamp
Life of this patent
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Abstract
An alternative resonant circuit configuration reduces the amount of RF current that is switched by the power-stage transistors of a T/R unit and thereby also significantly reduces the reliability risk. A parallel resonant antenna configuration of coils and capacitors reduces the RF current through the output stage push-pull transistor configuration to a small fraction of the RF current experienced by typical series resonant circuits. This circuit offers advantages of low cost, reliable impedance matching while reducing the volume necessary to perform the function.
Claims4
An antenna resonant circuit of a T/R unit which reduces the amount of current flowing through the output-power stage of the T/R unit comprising:
- an output-power stage of a T/R unit;
- a low Q series resonant circuit comprised of a series connected capacitor and an inductor for stimulating a main antenna circuit to oscillate with a resonant frequency;
- said main antenna circuit comprised of a parallel combination of a second inductor and a second capacitor connected in series with a third capacitor wherein said third capacitor is connected in series with said series connected capacitor and said parallel combination is connected in parallel with said series combination of said third and said series connected capacitor;
- and
- wherein said low Q series resonant circuit is connected in parallel with said output power stage of said T/R unit.
Dependencies are inferred from the claim text.