RADIO-FREQUENCY RECEIVER DEVICE, RADIO-FREQUENCY COMMUNICATION DEVICE, AND INTERROGATOR
First Claim
1. A radio-frequency receiver device including a plurality of receiver antenna elements for receiving information from a desired communication object, said radio-frequency receiver device comprising:
- an antenna switching portion configured to select at least one of said plurality of receiver antenna elements which receives a set of information transmitted from said desired communication object;
a received-information memory portion configured to store sets of information received by the plurality of receiver antenna elements sequentially selected by said antenna switching portion; and
a received-information combining portion configured to read out the sets of information from said received-information memory portion, and to combine together the sets of information read out from said received-information memory portion.
1 Assignment
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Accused Products
Abstract
A radio-frequency receiver device including a plurality of receiver antenna elements for receiving information from a desired communication object, the radio-frequency receiver device including an antenna switching portion configured to select at least one of the plurality of receiver antenna elements which receives a set of information transmitted from the desired communication object, a received-information memory portion configured to store sets of information received by the plurality of receiver antenna elements sequentially selected by the antenna switching portion, and a received-information combining portion configured to read out the sets of information from the received-information memory portion, and to combine together the read out sets of information read out from the received-information memory portion.
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Citations
51 Claims
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1. A radio-frequency receiver device including a plurality of receiver antenna elements for receiving information from a desired communication object, said radio-frequency receiver device comprising:
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an antenna switching portion configured to select at least one of said plurality of receiver antenna elements which receives a set of information transmitted from said desired communication object;
a received-information memory portion configured to store sets of information received by the plurality of receiver antenna elements sequentially selected by said antenna switching portion; and
a received-information combining portion configured to read out the sets of information from said received-information memory portion, and to combine together the sets of information read out from said received-information memory portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A radio-frequency communication device comprising:
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a plurality of antenna elements configured to receive in a non-contact fashion modulated signals which are transmitted from a signal transmitter device and which have a frequency f;
a memory portion configured to sequentially sample sets of data of said modulated signal received by said plurality of antenna elements or a signal obtained by conversion from said modulated signal and having a frequency fi, at a rate of 4nf or 4nfi (where n is a positive integer), and sequentially store the sampled sets of data, such that the last sampled set of data and a preceding set of data sampled an n-number of sampling cycles prior to the last sampled set of data are readable from said memory portion;
a transforming portion configured to obtain data of a complex signal by transformation from said last sampled set of data and said preceding set of data which are respectively used as a real-number portion and an imaginary-number portion of said complex signal; and
a control portion configured to change a directivity of said plurality of antenna elements on the basis of said data of the complex signal obtained by said transforming portion, such that said plurality of antenna elements have a maximum sensitivity of reception of said modulated signal from said signal transmitter device. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. An interrogator of a radio-frequency tag communication system, comprising:
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a plurality of antenna elements configured to receive in a non-contact fashion modulated signals which are transmitted from an IC-circuit portion of a circuit element of a radio-frequency tag and which have a frequency f;
a memory portion configured to sequentially sample sets of data of said modulated signal received by said plurality of antenna elements or a signal obtained by conversion from said modulated signal and having a frequency fi, at a rate of 4nf or 4nfi (where n is a positive integer), and sequentially store the sampled sets of data, such that the last sampled set of data and a preceding set of data sampled an n-number of sampling cycles prior to the last sampled set of data are readable from said memory portion;
a transforming portion configured to obtain data of a complex signal by transformation from said last sampled set of data and said preceding set of data which are respectively used as a real-number portion and an imaginary-number portion of said complex signal; and
a control portion configured to change a directivity of said plurality of antenna elements on the basis of said data of the complex signal obtained by said transforming portion, such that said plurality of antenna elements have a maximum sensitivity of reception of said modulated signal from said signal transmitter device. - View Dependent Claims (19)
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20. An interrogator of a radio-frequency communication system, comprising:
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a plurality of antenna elements configured to receive reply signals transmitted from a transponder;
a weighted-signal generating portion configured to generate a weighted signal by multiplying the received signals received by said plurality of antenna elements, by respective weights for controlling a directivity of said plurality of antenna elements so as to maximize a sensitivity of reception of the received signals by said plurality of antenna elements in a direction toward said transponder; and
a weight determining portion configured to determine said weights to be given to said weighted-signal generating portion such that a level of the weighted signal approaches a predetermined level of a target signal. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51)
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Specification