Abstract: A radio-frequency device includes a PAA processing portion configured to control a directivity of reception of a receiver antenna device, a received-signal-strength detecting portion configured to detect a strength of the received signal received by the receiver antenna device, and a direction detecting portion configured to detect the direction toward the communication object, on the basis of a direction in which a higher one of two strength values of the received signal respectively detected in first and second maximum-reception-directivity directions of a predetermined angular difference established by the PAA processing portion is minimal. Accordingly, the direction toward the radio-frequency tag can be suitably detected.

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

Abstract: A radio-frequency tag communication system including (a) a radio-frequency tag, (b) a radio-frequency tag communication device configured to transmit a transmitted signal toward the 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, and (c) at least one reference tag disposed fixedly in an area of communication of the radio-frequency tag communication system and configured to transmit a reply signal in response to the transmitted signal, for thereby effecting radio communication with the radio-frequency tag communication device, and wherein the radio-frequency tag communication device includes a directivity control portion configured to control a directivity of communication with the radio-frequency tag, on the basis of a result of the radio communication of the radio-frequency tag communication device with the at least one reference tag.

Abstract: A radio-frequency receiver device including receiver antenna elements each arranged to receive a signal from a desired communication object, a phased-array control portion to perform a phased array antenna control for controlling the directivity of reception of the signals by the receiver antenna elements, an adaptive-array control portion to perform an adaptive array antenna control for controlling the directivity of reception of the signals by the receiver antenna elements, a received-signal-quality determining portion to determine whether the signals received by the receiver antenna elements has a quality higher than a predetermined threshold, and a directivity control switching portion configured to enable the phased-array control portion to perform the phased array antenna controls, and to enable the adaptive-array control portion to perform the adaptive array antenna control only if a negative determination is obtained by the received-signal-quality determining portion after the phased array antenna con

Abstract: A radio-frequency tag communication device arranged 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, the radio-frequency tag communication device including (a) a receiver portion including a receiver antenna device which has a plurality of receiver antenna elements for receiving the reply signal from the radio-frequency tag, (b) a reception-directivity control portion which controls the directivity of reception of the receiver portion device, by controlling the phase of a received signal which is received by each of the plurality of receiver antenna elements and which may include a leakage signal which is a part of the transmitted signal, (c) a modulated-component extracting portion which extracts a modulated component of the received signal which is modulated by the radio-frequency tag, and (d) a direction detecting

Abstract: A radio-frequency tag communication system including (a) a radio-frequency tag, (b) a radio-frequency tag communication device configured to transmit a transmitted signal toward the 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, and (c) at least one reference tag disposed fixedly in an area of communication of the radio-frequency tag communication system and configured to transmit a reply signal in response to the transmitted signal, for thereby effecting radio communication with the radio-frequency tag communication device, and wherein the radio-frequency tag communication device includes a directivity control portion configured to control a directivity of communication with the radio-frequency tag, on the basis of a result of the radio communication of the radio-frequency tag communication device with the at least one reference tag.

Abstract: A radio-frequency tag communication device arranged 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, the radio-frequency tag communication device including (a) a receiver portion including a receiver antenna device which has a plurality of receiver antenna elements for receiving the reply signal from the radio-frequency tag, (b) a reception-directivity control portion which controls the directivity of reception of the receiver portion device, by controlling the phase of a received signal which is received by each of the plurality of receiver antenna elements and which may include a leakage signal which is a part of the transmitted signal, (c) a modulated-component extracting portion which extracts a modulated component of the received signal which is modulated by the radio-frequency tag, and (d) a direction detecting

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

Abstract: A radio-frequency device includes a PAA processing portion configured to control a directivity of reception of a receiver antenna device, a received-signal-strength detecting portion configured to detect a strength of the received signal received by the receiver antenna device, and a direction detecting portion configured to detect the direction toward the communication object, on the basis of a direction in which a higher one of two strength values of the received signal respectively detected in first and second maximum-reception-directivity directions of a predetermined angular difference established by the PAA processing portion is minimal.

Abstract: A radio-frequency receiver device including receiver antenna elements each arranged to receive a signal from a desired communication object, a phased-array control portion to perform a phased array antenna control for controlling the directivity of reception of the signals by the receiver antenna elements, an adaptive-array control portion to perform an adaptive array antenna control for controlling the directivity of reception of the signals by the receiver antenna elements, a received-signal-quality determining portion to determine whether the signals received by the receiver antenna elements has a quality higher than a predetermined threshold, and a directivity control switching portion configured to enable the phased-array control portion to perform the phased array antenna controls, and to enable the adaptive-array control portion to perform the adaptive array antenna control only if a negative determination is obtained by the received-signal-quality determining portion after the phased array antenna con

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.