Methods and apparatus for antenna signal limiter for radio frequency identification transponder
First Claim
1. A method, comprising:
- forming a first rectified signal from a received radio frequency signal, the first rectified signal having a constant level portion and a second portion corresponding to half of a waveform of the received radio frequency signal;
forming a second rectified signal from the received radio frequency signal having a constant level portion and a second waveform portion that is of opposite phase to the second portion of the first rectified signal;
determining a first power mode is active, in which the first power mode is an initialization mode, and if the first power mode is active, comparing the first rectified signal to a high voltage reference, and if the first rectified signal exceeds the high voltage reference, limiting the maximum voltage of the first rectified signal, and comparing the second rectified signal to the high voltage reference, and if the second rectified signal exceeds the high voltage reference, limiting the maximum voltage of the second rectified signal;
determining a second power mode is active, the second power mode being a band gap active mode, and if the second power mode is active, limiting the maximum voltage level of the first rectified signal and maximum voltage level of the second rectified signal to a positive voltage level of a power supply;
determining a third power mode is active, in which the third power mode is a power regulation mode, and if the third power mode is active, comparing the first rectified signal to a low voltage reference, and if the first rectified signal is less than the low voltage reference, limiting the minimum voltage of the first rectified signal, and comparing the second rectified signal to the low voltage reference, and if the second rectified signal is less than the low voltage reference, limiting the minimum voltage of the second rectified signal.
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Accused Products
Abstract
In described examples, an apparatus includes: at least one resonant circuit for receiving a radio frequency signal; a rectifier coupled to the resonant circuit to output a first rectified signal with a constant level portion and a portion matching a first portion of the radio frequency signal, and to output a second rectified signal having a constant level portion and a portion that matches a second portion of the radio frequency signal; a first limiter circuit to limit a voltage of the first rectified signal to a predetermined maximum voltage level; a second limiter circuit to limit the voltage of the second rectified signal to the predetermined maximum voltage level; a third limiter circuit to limit a voltage of the first rectified signal to a predetermined minimum voltage level; and a fourth limiter circuit to limit the voltage of the second rectified signal to the predetermined minimum voltage level.
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Citations
20 Claims
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1. A method, comprising:
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forming a first rectified signal from a received radio frequency signal, the first rectified signal having a constant level portion and a second portion corresponding to half of a waveform of the received radio frequency signal; forming a second rectified signal from the received radio frequency signal having a constant level portion and a second waveform portion that is of opposite phase to the second portion of the first rectified signal; determining a first power mode is active, in which the first power mode is an initialization mode, and if the first power mode is active, comparing the first rectified signal to a high voltage reference, and if the first rectified signal exceeds the high voltage reference, limiting the maximum voltage of the first rectified signal, and comparing the second rectified signal to the high voltage reference, and if the second rectified signal exceeds the high voltage reference, limiting the maximum voltage of the second rectified signal; determining a second power mode is active, the second power mode being a band gap active mode, and if the second power mode is active, limiting the maximum voltage level of the first rectified signal and maximum voltage level of the second rectified signal to a positive voltage level of a power supply; determining a third power mode is active, in which the third power mode is a power regulation mode, and if the third power mode is active, comparing the first rectified signal to a low voltage reference, and if the first rectified signal is less than the low voltage reference, limiting the minimum voltage of the first rectified signal, and comparing the second rectified signal to the low voltage reference, and if the second rectified signal is less than the low voltage reference, limiting the minimum voltage of the second rectified signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus, comprising
at least one resonant circuit for receiving a radio frequency signal; -
a rectifier coupled to the resonant circuit to output a first rectified signal having a waveform with a constant level portion and a portion matching a first portion of the radio frequency signal, and to output a second rectified signal having a constant level portion and a portion that matches a second portion of the radio frequency signal and is out of phase with the first rectified signal; a first limiter circuit coupled to the first rectified signal to limit a voltage of the first rectified signal to a predetermined maximum voltage level; a second limiter circuit coupled to the second rectified signal to limit the voltage of the second rectified signal to the predetermined maximum voltage level; a third limiter circuit coupled to the first rectified signal to limit a voltage of the first rectified signal to a predetermined minimum voltage level; and a fourth limiter circuit coupled to the second rectified signal to limit the voltage of the second rectified signal to the predetermined minimum voltage level. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. An integrated circuit transponder, comprising:
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a rectifier circuit coupled to a receive radio frequency signals from at least a first resonant circuit, and to form a first rectified signal and to form a second rectified signal; a first limiter circuit coupled to the first rectified signal to limit a voltage of the first rectified signal to a predetermined maximum voltage level; a second limiter circuit coupled to the second rectified signal to limit a voltage of the second rectified signal to the predetermined maximum voltage level; a third limiter circuit coupled to the first rectified signal to limit the voltage of the first rectified signal to a predetermined minimum voltage level; and a fourth limiter circuit coupled to the second rectified signal to limit the voltage of the second rectified signal to the predetermined minimum voltage level. - View Dependent Claims (19, 20)
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Specification