Transceiver
First Claim
1. A transceiver including:
- a single antenna adapted for simultaneously receiving a first signal and transmitting a second signal;
a signal processor for receiving from the antenna a third signal indicative of the first signal; and
a modulator disposed between the antenna and the signal processor for providing a fourth signal to the antenna for forming the second signal, the modulator varying the impedance between the antenna and the signal processor for providing the antenna with a simultaneous dual Q-factor, the Q-factor being high for the first signal and low for the second signal.
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0 Petitions
Accused Products
Abstract
A transceiver according to the invention has application to a baggage handling system, amongst others, and includes an electrical circuit having a modulated series resistor, in the form of resistor R(modulator). Also included is a parallel switch SW1, which is placed between the antenna and a storage capacitor in the AC part of the circuit. In other embodiments the modulated series resistor, again in the form of resistor R(modulator) and parallel switch SW1, is placed between the antenna and the storage capacitor in the DC part of the circuit. Both circuits produce the same transmitted signal, although in practice the latter is simpler to implement due to its DC operating bias. In still further embodiments a modulated series resistor is placed between the antenna and the antenna'"'"'s tuning capacitor.
33 Citations
35 Claims
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1. A transceiver including:
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a single antenna adapted for simultaneously receiving a first signal and transmitting a second signal; a signal processor for receiving from the antenna a third signal indicative of the first signal; and a modulator disposed between the antenna and the signal processor for providing a fourth signal to the antenna for forming the second signal, the modulator varying the impedance between the antenna and the signal processor for providing the antenna with a simultaneous dual Q-factor, the Q-factor being high for the first signal and low for the second signal.
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2. A transceiver including:
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a single antenna adapted for simultaneously receiving a first radio frequency (RF) electromagnetic signal and transmitting a second RF electromagnetic signal; a signal processor for receiving from the antenna a third electrical signal based on the first RF electromagnetic signal; a modulator disposed in series between the antenna and the signal processor for providing a fourth electrical signal to the antenna to produce the second RF electromagnetic signal, the modulator varying the series impedance between the antenna and the signal processor; and wherein the modulator varies the impedance between the antenna and the signal processor, such that the antenna simultaneously has a high Q factor for signals received by the antenna and a low Q factor for signals transmitted from the antenna. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for operating a transceiver including the steps of:
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providing a single antenna adapted for simultaneously receiving a first radio frequency (RF) electromagnetic signal and transmitting a second RF electromagnetic signal; providing a signal processor for receiving from the antenna a third electrical signal based on the first RF electromagnetic signal; providing an impedance for modulation, via a modulator, the modulator being disposed in series between the antenna and the signal processor; providing a fourth electrical signal to the antenna to produce the second RF electromagnetic signal; varying the impedance between the antenna and the signal processor; and wherein the step of varying provides the antenna with a simultaneous dual Q-factor, the Q-factor being high for the first RF electromagnetic signal and low for the second RF electromagnetic signal.
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14. A passive transponder including:
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a single antenna adapted for simultaneously receiving and transmitting a first radio frequency (RF) electromagnetic signal and a second RF electromagnetic signal respectively; a signal processor for; receiving a third electrical signal from the antenna which is derived from the first RF electromagnetic signal; and providing a fourth electrical signal derived from the third electrical signal; a power storage means in parallel with the signal processor for absorbing some of the power of the third electrical signal, the absorbed power being subsequently used by the transponder; a modulator disposed in series between the antenna and the power storage means for selectively varying the impedance therebetween to generate the second RF electromagnetic signal and provide the antenna with a simultaneous dual Q-factor, the Q-factor being high for the first RF electromagnetic signal and low for the second RF electromagnetic signal; and a mixer for producing a fifth signal by combining the fourth electrical signal with a sub-carrier, the fifth signal being provided to the modulator. - View Dependent Claims (15, 16, 17)
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18. An antenna adapted for simultaneously receiving and transmitting a first radiofrequency (RF) electromagnetic signal and a second RF electromagnetic signal respectively, the antenna including:
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a tuned coil in which the first signal generates a first current and which supports a second current for generating said second signal; and a modulator disposed in series with the coil, said first and second currents flowing through said modulator for providing said coil with a simultaneous dual Q factor, the Q factor being high for the first current and low for the second current. - View Dependent Claims (19, 20)
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21. A transceiver including:
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a single antenna adapted for simultaneously receiving a first radio frequency (RF) electromagnetic signal and transmitting a second RF electromagnetic signal; a signal processor for receiving from the antenna a third electrical signal indicative of the first signal; and a modulator disposed in series between the antenna and the signal processor for providing a fourth electrical signal to the antenna to produce the second signal, the modulator varying the voltage across the antenna in a substantially stepwise manner to effect a variation in the current flowing through the antenna between a low and a high value for allowing transmission of the second signal without substantially affecting the receiving efficiency of the antenna, wherein the modulator is adapted to further provide the antenna with a simultaneous dual Q-factor, the Q-factor being high for the first RF electromagnetic signal and low for the second RF electromagnetic signal. - View Dependent Claims (22)
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23. A method for operating a transceiver including the steps of:
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providing an antenna adapted for simultaneously receiving a first radio frequency (RF) electromagnetic signal and transmitting a second RF electromagnetic signal; providing a signal processor for receiving from the antenna a third electrical signal based on the first signal; providing a modulator disposed in series between the antenna and the signal processor; providing a fourth electrical signal to the antenna to produce the second signal; varying the impedance of the modulator, thereby to vary the voltage across the antenna in a substantially stepwise manner to effect a variation in the current flowing through the antenna between a low and a high value for allowing transmission of the second signal without substantially effecting the receiving efficiency of the antenna; and wherein the step of varying provides the antenna with a simultaneous dual Q-factor, the Q-factor being high for the first RF electromagnetic signal and low for the second electrical signal.
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24. A transceiver including:
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a single antenna adapted for simultaneously receiving a first radio frequency (RF) electromagnetic signal having a first predetermined frequency and, in response thereto, generating a second electrical signal; receiving circuitry being responsive to the second signal; tuning circuitry for providing the antenna with a resonant frequency at or about the first predetermined frequency; and a modulator disposed in series between the antenna and the tuning circuitry for varying the impedance therebetween such that the second signal generates a third electrical signal in the antenna at a second predetermined frequency and the antenna transmits a fourth RF electromagnetic signal derived from the third signal; and wherein the modulator is adapted to provide the antenna with a simultaneous dual Q-factor, the Q-factor being high for the first RF electromagnetic signal and low for the second RF electromagnetic signal. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A transceiver including:
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a single antenna adapted for simultaneously receiving a first signal and transmitting a second signal, the antenna being a tuned coil in which the first signal generates a first current and which supports a second current for generating the second signal; a signal processor for receiving from the antenna a third signal indicative of the first signal; and a modulator disposed between the antenna and the signal processor for providing a fourth signal to the antenna for forming the second signal, the modulator varying the impedance between the antenna and the signal processor for providing the antenna with a simultaneous dual Q-factor, the Q-factor being high for the first signal and low for the second signal.
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35. A transponder including:
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a single antenna adapted for simultaneously receiving a first signal and transmitting a second signal, the first and second signals are modulated at a first frequency and a second frequency, respectively, the first and second frequencies being different to each other; a signal processor for receiving from the antenna a third signal indicative of the first signal; and a modulator disposed between the antenna and the signal processor for providing a fourth signal to the antenna for forming the second signal, the modulator varying the impedance between the antenna and the signal processor for providing the antenna with a simultaneous dual Q-factor, the Q-factor being high for the first signal and low for the second signal.
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Specification