Abstract: An object detection apparatus includes: a transmitter transmitting a radio wave with a predetermined intensity at the radio wave transmission end; a receiver receiving the radio wave, which is to be transmitted when the radio wave is transmitted from the transmitter, at the radio wave reception end; a setter setting a transmission scheme of the transmitter to a plurality of different transmission characteristics; a transmission controller controlling the transmitter to transmit the radio wave with the transmission scheme, which is to be set when the setter sets the transmission scheme; and a detector detecting a presence of the object at a position inside the vehicle, based on a detected reception intensity indicating a respective radio wave reception intensity received by the receiver, the object blocking the radio wave transmitted from the transmitter to the receiver at the position inside the vehicle.

Abstract: A light-transmissive antenna includes: a transparent base made of a transparent insulating material; and an antenna pattern formed on the transparent base. The antenna pattern is made of a transparent electrically conductive film that is a film-like member having a predetermined transmittance and a predetermined electrical conductivity. The light-transmissive antenna includes a plurality of highly electrically conductive patterns arranged on the antenna pattern, each of the highly electrically conductive patterns being made of an electrically conducive member having a higher electrical conductivity than the transparent electrically conductive film and formed in a linear shape. Each of the plurality of highly electrically conductive patterns has a predetermined width set equal to or smaller than a value assumed as a resolution of human eyes.

Abstract: An antenna device includes a ground part, a patch part disposed parallel to the ground part to oppose the ground part, a short-circuit part electrically connecting the patch part and the ground part, a patch area expansion part and a ground area expansion part. The patch area expansion part is provided on a patch-side opposing surface that is a surface of the patch part opposing the ground part to expand an effective surface area that is an apparent area of the patch-side opposing surface with respect to the ground part. The ground area expansion part is provided in a region opposing the patch area expansion part on a ground-side opposing surface that is a surface of the ground part opposing the patch part to expand an effective surface area of the ground-side opposing surface with respect to the patch part.

Abstract: An object detection apparatus includes: a transmitter transmitting a radio wave with a predetermined intensity at the radio wave transmission end; a receiver receiving the radio wave, which is to be transmitted when the radio wave is transmitted from the transmitter, at the radio wave reception end; a setter setting a transmission scheme of the transmitter to a plurality of different transmission characteristics; a transmission controller controlling the transmitter to transmit the radio wave with the transmission scheme, which is to be set when the setter sets the transmission scheme; and a detector detecting a presence of the object at a position inside the vehicle, based on a detected reception intensity indicating a respective radio wave reception intensity received by the receiver, the object blocking the radio wave transmitted from the transmitter to the receiver at the position inside the vehicle.

Abstract: In an antenna, a first element is connected to a GND of a feeder, on the same plane as a GND of a wireless circuit, and isolated from the GND of the wireless circuit. A second element is on the same plane as the GND of the wireless circuit and a first end connected to the first element and a second end as an open end. The third element has a first end connected to a power source of the feeder and located in a region occupied by the first element perpendicularly to the first element so that its first end source faces down. The fourth element has a first end connected to a second end of the third element and a second end as an open end, is parallel to the first element, and is perpendicular to a line connecting the first and second ends of the second element.

Abstract: In an antenna, a first element is connected to a GND of a feeder, on the same plane as a GND of a wireless circuit, and isolated from the GND of the wireless circuit. A second element is on the same plane as the GND of the wireless circuit and a first end connected to the first element and a second end as an open end. The third element has a first end connected to a power source of the feeder and located in a region occupied by the first element perpendicularly to the first element so that its first end source faces down. The fourth element has a first end connected to a second end of the third element and a second end as an open end, is parallel to the first element, and is perpendicular to a line connecting the first and second ends of the second element.

Abstract: An antenna apparatus includes: a ground substrate; and a loop antenna having first and second polarized wave surfaces, which are perpendicular to the substrate. The substrate provides an antenna, which is excited and vibrated together with the loop antenna. The antenna has a first polarized wave component in parallel to the first polarized wave surface and a second polarized wave component in parallel to the second polarized wave surface. A polarized wave ratio between the first polarized wave component and the second polarized wave component in the substrate is substantially equal to a polarized wave ratio between the first polarized wave surface and the second polarized wave surface in the loop antenna.

Abstract: In a wireless communication apparatus, when a first switch electrically connects a second antenna to an impedance matching circuit and a second switch electrically connects a first antenna to a reception circuit, a frequency signal output from an oscillator of the reception circuit is received by the second antenna and applied to the impedance matching circuit. Then, a controller controls the impedance of the impedance matching circuit so as to bring a RSSI voltage output from a signal strength detection circuit of the reception circuit into agreement with a reference RSSI voltage, thereby bringing the reference frequency of the first antenna into agreement with a reference frequency.

Abstract: A matching circuit, connected to a receiving antenna and to the input of a receiving circuit, incorporates a variable capacitor that is adjustable for tuning the resonance frequency of the antenna to a desired reception frequency. In an automatic tuning mode of operation, an oscillator signal of different frequency from the reception frequency is applied to induce resonance of the antenna and matching circuit, and the variable capacitor is adjusted until an output signal level from the receiving circuit attains a predetermined value which has been stored beforehand in a memory and which corresponds to a condition whereby the antenna resonance frequency corresponds to the reception frequency and impedance matching exists between the antenna and receiving circuit.

Abstract: In a wireless communication apparatus, when a first switch electrically connects a second antenna to an impedance matching circuit and a second switch electrically connects a first antenna to a reception circuit, a frequency signal output from an oscillator of the reception circuit is received by the second antenna and applied to the impedance matching circuit. Then, a controller controls the impedance of the impedance matching circuit so as to bring a RSSI voltage output from a signal strength detection circuit of the reception circuit into agreement with a reference RSSI voltage, thereby bringing the reference frequency of the first antenna into agreement with a reference frequency.

Abstract: A matching circuit, connected to a receiving antenna and to the input of a receiving circuit, incorporates a variable capacitor that is adjustable for tuning the resonance frequency of the antenna to a desired reception frequency. In an automatic tuning mode of operation, an oscillator signal of different frequency from the reception frequency is applied to induce resonance of the antenna and matching circuit, and the variable capacitor is adjusted until an output signal level from the receiving circuit attains a predetermined value which has been stored beforehand in a memory and which corresponds to a condition whereby the antenna resonance frequency corresponds to the reception frequency and impedance matching exists between the antenna and receiving circuit.

Abstract: An electromagnetic impedance sensor detects an object made of conducting material or soft magnetic material with contact-free. The sensor includes: a detection coil; and a detection circuit for supplying electricity to the coil and for measuring electromagnetic impedance change in the coil. The detection coil includes multiple coil portions provided by one wire. One coil portion has a side adjacent to a corresponding side of another coil portion. The side and the corresponding side extend along with a direction, and the side has a current flowing direction, which is the same as the corresponding side.

Abstract: An antenna apparatus includes: a ground substrate; and a loop antenna having first and second polarized wave surfaces, which are perpendicular to the substrate. The substrate provides an antenna, which is excited and vibrated together with the loop antenna. The antenna has a first polarized wave component in parallel to the first polarized wave surface and a second polarized wave component in parallel to the second polarized wave surface. A polarized wave ratio between the first polarized wave component and the second polarized wave component in the substrate is substantially equal to a polarized wave ratio between the first polarized wave surface and the second polarized wave surface in the loop antenna.

Abstract: A collision detector includes a deformable portion and a planar sensor accompanied by a process circuit and a collision determination unit. The deformable portion is configured to be deformed on a collision on an object. The planar sensor has a planar coil formed as a planar winding of winding wire to be deformed along the deformation of the deformable portion. The process circuit generates an electric signal that is in proportion to a self inductance Ls of the planar coil. The collision determination unit determines whether the object collided with the deformable member based on the change of the electric signal.

Abstract: An electromagnetic impedance sensor detects an object made of conducting material or soft magnetic material with contact-free. The sensor includes: a detection coil; and a detection circuit for supplying electricity to the coil and for measuring electromagnetic impedance change in the coil. The detection coil includes multiple coil portions provided by one wire. One coil portion has a side adjacent to a corresponding side of another coil portion. The side and the corresponding side extend along with a direction, and the side has a current flowing direction, which is the same as the corresponding side.