RADIO-FREQUENCY TAG COMMUNICATION DEVICE
First Claim
1. A radio-frequency tag communication device configured to transmit a transmitted signal toward a radio-frequency tag, and to receive a reply signal transmitted from the radio-frequency tag in response to the transmitted signal, for thereby effecting radio communication with the radio-frequency tag, said radio-frequency tag communication system comprising:
- a receiver array antenna device consisting of a plurality of antenna elements each provided for receiving said reply signal;
a cancel-signal generating portion configured to generate a cancel signal for eliminating a leakage signal that is a part of said transmitted signal, which part is received by said receiver array antenna device;
a cancel-signal control portion configured to control a phase and/or an amplitude of said cancel signal generated by said cancel-signal generating portion; and
a received-signal combining portion configured to combine together received signals received by said plurality of antenna elements, to obtain a composite signal,said radio-frequency tag communication device being configured to concurrently control the transmission of said transmitted signal and the reception of said received signals, and to apply said cancel signal generated by said cancel-signal generating portion to said received-signal combining portion, for combining together the received signals and the cancel signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A radio-frequency tag communication device including a receiver array antenna device for receiving a reply signal, a cancel-signal generating portion configured to generate a cancel signal for eliminating a leakage signal that is a part of a transmitted signal, which part is received by the receiver array antenna device, a cancel-signal control portion configured to control a phase and/or an amplitude of the cancel signal generated by the cancel-signal generating portion, and a received-signal combining portion configured to combine together received signals received by a plurality of antenna elements of the receiver array antenna device, to obtain a composite signal, and wherein the transmission of the transmitted signal and the reception of the received signals are concurrently controlled, and the cancel signal generated by the cancel-signal generating portion is applied to the received-signal combining portion, whereby the received signals and the cancel signal are combined together, so that a signal/noise ratio of a wave detector output upon demodulation of the composite signal is improved to increase the maximum distance of communication.
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Citations
13 Claims
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1. A radio-frequency tag communication device configured to transmit a transmitted signal toward a radio-frequency tag, and to receive a reply signal transmitted from the radio-frequency tag in response to the transmitted signal, for thereby effecting radio communication with the radio-frequency tag, said radio-frequency tag communication system comprising:
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a receiver array antenna device consisting of a plurality of antenna elements each provided for receiving said reply signal; a cancel-signal generating portion configured to generate a cancel signal for eliminating a leakage signal that is a part of said transmitted signal, which part is received by said receiver array antenna device; a cancel-signal control portion configured to control a phase and/or an amplitude of said cancel signal generated by said cancel-signal generating portion; and a received-signal combining portion configured to combine together received signals received by said plurality of antenna elements, to obtain a composite signal, said radio-frequency tag communication device being configured to concurrently control the transmission of said transmitted signal and the reception of said received signals, and to apply said cancel signal generated by said cancel-signal generating portion to said received-signal combining portion, for combining together the received signals and the cancel signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification