Power supply circuitry for a transponder and operable with infinitesimal power from receiving antenna
First Claim
1. Power supply circuitry for a transponder and connected to receiving means for receiving electromagnetic energy and a response circuit connected to said receiving means for transmitting a signal in response to received electromagnetic energy, said power supply circuitry generating DC power to be fed to said response circuit out of the received electromagnetic energy, said power supply circuitry comprising:
- a first rectifier diode having a junction formed by an n type semiconductor region and a p type semiconductor region, and adjusted such that a reverse resistance against a reverse current directed from said n type semiconductor region toward said p type semiconductor region is lower than a forward resistance against a forward current directed from said p type semiconductor region toward said n type semiconductor region;
said first rectifier diode being connected between said receiving means and said response circuit;
whereby a voltage output from said receiving means received the electromagnetic energy is applied to said first rectifier diode to thereby cause the reverse current to flow through said first rectifier diode, and a resulting DC voltage output from said first rectifier diode causes power to be fed to said response circuit.
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Accused Products
Abstract
In a transponder, power supply circuitry is connected to an antenna and a response circuit. DC power to be fed to the response circuit is generated out of an electromagnetic wave come in through the antenna. A rectifier diode has an n type and a p type semiconductor region and is adjusted such that a reverse resistance against a reverse current directed from the n type region toward the p type region is lower than a forward resistance against a forward current directed from the latter region to the former region. A voltage output from the antenna on the receipt of the electromagnetic wave is applied to the rectifier diode, thereby causing a reverse current to flow to the diode. The resulting DC voltage is used to feed power to the response circuit. Even when the electromagnetic wave received from an interrogator is weak, sufficient power can be surely fed to the response circuit.
66 Citations
15 Claims
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1. Power supply circuitry for a transponder and connected to receiving means for receiving electromagnetic energy and a response circuit connected to said receiving means for transmitting a signal in response to received electromagnetic energy, said power supply circuitry generating DC power to be fed to said response circuit out of the received electromagnetic energy, said power supply circuitry comprising:
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a first rectifier diode having a junction formed by an n type semiconductor region and a p type semiconductor region, and adjusted such that a reverse resistance against a reverse current directed from said n type semiconductor region toward said p type semiconductor region is lower than a forward resistance against a forward current directed from said p type semiconductor region toward said n type semiconductor region; said first rectifier diode being connected between said receiving means and said response circuit; whereby a voltage output from said receiving means received the electromagnetic energy is applied to said first rectifier diode to thereby cause the reverse current to flow through said first rectifier diode, and a resulting DC voltage output from said first rectifier diode causes power to be fed to said response circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A transponder comprising:
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receiving means for receiving electromagnetic energy sent from an interrogator; a response circuit connected to said receiving means, and for transmitting a signal to the interrogator in response to the electromagnetic energy received; and power supply circuitry connected to said receiving means and said response circuit, and for generating DC power to be applied to said response circuit out of the electromagnetic energy received; said power supply circuitry comprising; a first rectifier diode having a junction formed by an n type semiconductor region and a p type semiconductor region, and adjusted such that a reverse resistance against a reverse current directed from said n type semiconductor region toward said p type semiconductor region is lower than a forward resistance against a forward current directed from said p type semiconductor region toward said n type semiconductor region; said first rectifier diode being connected between said receiving means and said response circuit; whereby a voltage output from said receiving means received the electromagnetic energy is applied to said first rectifier diode to thereby cause the reverse current to flow through said first rectifier diode, and a resulting DC voltage output from said first rectifier diode causes power to be fed to said response circuit. - View Dependent Claims (15)
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Specification