Abstract: A reading system includes an evaluation value acquirer and a determining processor. The evaluation value acquirer is configured to acquire, with regard to a reading device configured to perform wireless communication with an electronic tag attached to each of one or more items by using a radio wave as a medium to read item information on each of one or more items, an evaluation value about at least one of: the number of times; a time interval; or a frequency, of reading the item information for each of at the one or more items. The determining processor is configured to determine, for each of the one or more items, whether or not each of the one or more items is an object to be read based on a change in the evaluation value over time.

Abstract: A wireless reading system includes a goods path and a reader device. The goods path allows one or more goods held by a customer passing through a customer path to be moved along. The reader device is configured to perform wireless communication, whose medium is radio waves, with one or more electronic tags attached to the one or more goods while the one or more goods are moved along the goods path, thereby reading one or more pieces of goods information on the one or more goods, respectively.

Abstract: A reading system includes an evaluation value acquirer and a determining processor. The evaluation value acquirer is configured to acquire, with regard to a reading device configured to perform wireless communication with an electronic tag attached to each of one or more items by using a radio wave as a medium to read item information on each of one or more items, an evaluation value about at least one of: the number of times; a time interval; or a frequency, of reading the item information for each of at the one or more items. The determining processor is configured to determine, for each of the one or more items, whether or not each of the one or more items is an object to be read based on a change in the evaluation value over time.

Abstract: A wireless communications system according to an aspect includes a communications terminal, a detection unit, and a control unit. The communications terminal includes a communications unit to communicate wirelessly with a communications partner terminal. The detection unit detects movement of the communications terminal. The control unit controls the communications terminal so as to vary a communicable area of the communications unit. The communicable area is defined relatively to the communications terminal. The control unit varies the communicable area according to at least magnitude of the movement detected by the detection unit.

Abstract: A shopping assistance system includes a strength acquirer and a determining processor. The strength acquirer is configured to acquire values of a received signal strength indication at a reader device while the reader device performs wireless communication with an electronic tag attached to at least one product. The reader device is configured to perform the wireless communication with the electronic tag by using a radio wave as a medium to read a piece of product information on the at least one product. The determining processor is configured to determine, for each of the at least one product, whether or not the at least one product is an object to be purchased based on a change of the received signal strength indication over time.

Abstract: An information acquisition system includes an inner wall, an outer wall, and an antenna. The inner wall includes a reflective layer which reflects a radio wave. A reading space is located on an inner side of the reflective layer. Reading of tag information from an RF tag attached to an item is performed in the reading space. The outer wall is disposed on an opposite side of the inner wall from the reading space. The antenna is configured to output the radio wave toward the reading space in order to communicate with the RF tag. Between the inner wall and the outer wall, a peripheral space is provided. The reflective layer of the inner wall has a hole. The hole penetrates through the reflective layer in a thickness direction of the reflective layer.

Abstract: A wireless communications system according to an aspect includes a communications terminal, a detection unit, and a control unit. The communications terminal includes a communications unit to communicate wirelessly with a communications partner terminal. The detection unit detects movement of the communications terminal. The control unit controls the communications terminal so as to vary a communicable area of the communications unit. The communicable area is defined relatively to the communications terminal. The control unit varies the communicable area according to at least magnitude of the movement detected by the detection unit.

Abstract: A wireless reading system includes a goods path and a reader device. The goods path allows one or more goods held by a customer passing through a customer path to be moved along. The reader device is configured to perform wireless communication, whose medium is radio waves, with one or more electronic tags attached to the one or more goods while the one or more goods are moved along the goods path, thereby reading one or more pieces of goods information on the one or more goods, respectively.

Abstract: A power amplification apparatus generates a code for controlling the number of class D power amplifiers that are in operation among a plurality of class D power amplifiers, changes the duty ratio of a carrier wave signal in accordance with output voltage, and amplifies a transmission signal. A code for decreasing the number of class D power amplifiers in operation is generated when the duty ratio of the carrier wave signal is increased, while a code for increasing the number of class D power amplifiers in operation is generated when the duty ratio of the carrier wave signal is decreased.

Abstract: A quadrature modulator includes a first switched capacitor power amplifier that amplifies a first high-frequency signal, a second switched capacitor power amplifier that amplifies a second high-frequency signal, a first combiner which includes at least one pair of winding wires, one winding wire in one pair being disposed on a primary side to which the amplified first high-frequency signal and the amplified second high-frequency signal are separately input and the other winding wire in the one pair being disposed on a secondary side, the first combiner combining the input amplified first high-frequency signal and the input amplified second high-frequency signal to generate a quadrature modulation signal from the secondary side, a first inductor disposed between the first switched capacitor power amplifier and the primary side of the first combiner, and a second inductor disposed between the second switched capacitor power amplifier and the primary side of the first combiner.

Abstract: A power amplification device includes: a first power-amplifier array including a plurality of first switching elements that constitute a class-D power amplifier for a higher bits; a second power-amplifier array including a plurality of second switching elements that constitute a class-D power amplifier for a lower bits; and a capacitor array including a plurality of capacitance elements. The second switching elements have a larger on-resistance than the first switching elements. The first power-amplifier array is arranged between the second power-amplifier array and the capacitor array.

Abstract: A harmonic rejection mixer is disclosed that is capable of supporting wideband reception without any increase in circuit area. In this apparatus, transistors convert an RF signal to currents. Transistors perform frequency conversion based on the currents from the transistors and local oscillation signals. Transistors distribute the currents from the transistors to all transistors or some transistors based on a predetermined ratio. A load adds up the currents from the transistors and converts the resultant current to a voltage.

Abstract: A transmitting apparatus and transmission method are capable of easily and correctly mixing an in-phase component and a quadrature-phase component in a quadrature modulator. A local signal with a duty ratio of 25% or smaller is generated without using frequency which is a multiple of frequency of the local signal. Without providing switches in series to the outputs of I and Q amplifiers, a duty ratio of 25% or less is obtained. for the local signal, and class-D unit amplifiers are operated such that one of the I amplifier and the Q amplifier is connected to the output side in any state regardless of whether an output power control signal is at an on-level or an off-level. In producing the 25% duty ratio, a local signal with a 50% duty ratio is converted so as to have a duty ratio of 25% by I and Q duty converters.

Abstract: A power amplification apparatus generates a code for controlling the number of class D power amplifiers that are in operation among a plurality of class D power amplifiers, changes the duty ratio of a carrier wave signal in accordance with output voltage, and amplifies a transmission signal. A code for decreasing the number of class D power amplifiers in operation is generated when the duty ratio of the carrier wave signal is increased, while a code for increasing the number of class D power amplifiers in operation is generated when the duty ratio of the carrier wave signal is decreased.

Abstract: A power amplification device includes: a first power-amplifier array including a plurality of first switching elements that constitute a class-D power amplifier for a higher bits; a second power-amplifier array including a plurality of second switching elements that constitute a class-D power amplifier for a lower bits; and a capacitor array including a plurality of capacitance elements. The second switching elements have a larger on-resistance than the first switching elements. The first power-amplifier array is arranged between the second power-amplifier array and the capacitor array.

Abstract: A received is disclosed that is capable of improving reception sensitivity while avoiding an increase in circuit scale. The receiver includes: a multi-phase local oscillation signal generating section that generates a plurality of local oscillation signals of different phases; a phase selection signal generating section that generates a phase selection signal used to select a baseband signal of a predetermined phase based on a detection result of a reception level of a high-frequency signal; and a frequency converter that frequency-converts the high-frequency signal based on the plurality of local oscillation signals, that generates a plurality of baseband signals of different phases, and that selects a baseband signal from among the plurality of baseband signals based on the phase selection signal.

Abstract: A quadrature modulator includes a first switched capacitor power amplifier that amplifies a first high-frequency signal having a first phase, a second switched capacitor power amplifier that amplifies a second high-frequency signal having a second phase different from the first phase, a first combiner which includes at least one pair of winding wires that are magnetically coupled to each other, one winding wire in one pair being disposed on a primary side to which the amplified first high-frequency signal and the amplified second high-frequency signal are separately input and the other winding wire in the one pair being disposed on a secondary side, the first combiner combining the input amplified first high-frequency signal and the input amplified second high-frequency signal to generate a quadrature modulation signal from the secondary side, a first inductor disposed between the first switched capacitor power amplifier and the primary side of the first combiner, and a second inductor disposed between the se

Abstract: A transmitting apparatus and transmission method are capable of easily and correctly mixing an in-phase component and a quadrature-phase component in a quadrature modulator. A local signal with a duty ratio of 25% or smaller is generated without using frequency which is a multiple of frequency of the local signal. Without providing switches in series to the outputs of I and Q amplifiers, a duty ratio of 25% or less is obtained. for the local signal, and class-D unit amplifiers are operated such that one of the I amplifier and the Q amplifier is connected to the output side in any state regardless of whether an output power control signal is at an on-level or an off-level. In producing the 25% duty ratio, a local signal with a 50% duty ratio is converted so as to have a duty ratio of 25% by I and Q duty converters.

Abstract: A harmonic rejection mixer is disclosed that is capable of supporting wideband reception without any increase in circuit area. In this apparatus, transistors convert an RF signal to currents. Transistors perform frequency conversion based on the currents from the transistors and local oscillation signals. Transistors distribute the currents from the transistors to all transistors or some transistors based on a predetermined ratio. A load adds up the currents from the transistors and converts the resultant current to a voltage.

Abstract: A received is disclosed that is capable of improving reception sensitivity while avoiding an increase in circuit scale. The receiver includes: a multi-phase local oscillation signal generating section that generates a plurality of local oscillation signals of different phases; a phase selection signal generating section that generates a phase selection signal used to select a baseband signal of a predetermined phase based on a detection result of a reception level of a high-frequency signal; and a frequency converter that frequency-converts the high-frequency signal based on the plurality of local oscillation signals, that generates a plurality of baseband signals of different phases, and that selects a baseband signal from among the plurality of baseband signals based on the phase selection signal.