Abstract: The resistance detection sensor is configured to detect the electrical resistance value of a liquid. This resistance detection sensor includes a pair of electrodes, a DC voltage application unit, an AC voltage application unit, and a control unit. The pair of electrodes are immersed in a liquid. The DC voltage application unit applies a DC voltage having a first polarity between the pair of electrodes. The AC voltage application unit applies an AC voltage between the pair of electrodes. The control unit calculates the electrical resistance value of the liquid, in a state where the DC voltage is applied between the pair of electrodes by the DC voltage application unit. The control unit controls the AC voltage application unit so as to apply an AC voltage starting from a second polarity opposite to the first polarity at a predetermined time interval between the pair of electrodes.

Abstract: An oil condition determination system includes a resistance value measurement unit and a determination unit. The resistance value measurement unit applies a measurement voltage between a pair of measurement electrodes in contact with oil to measure a resistance value of the oil. The determination unit determines, when a change tendency of the resistance value of the oil is reversed, that condition of the oil is changed.

Abstract: Provided is a liquid sensor or the like that is relatively easy to manufacture. The liquid sensor includes a light emitting element, an optical waveguide, a light receiving element, and a detection circuit. The optical waveguide includes a first pillar portion, a first metal plate, a second pillar portion, and a second metal plate. The first metal plate is embedded in the first pillar portion. The second pillar portion is provided at a position opposing the first pillar portion. The second metal plate is embedded in the second pillar portion. A space for liquid is formed between the first pillar portion and the second pillar portion. The first pillar portion includes a first end surface that faces the light emitting element. The first metal plate includes a first reflecting portion that is tilted relative to the first end surface and reflects light toward the second pillar portion. The second pillar portion includes a second end surface that faces the light receiving element.

Abstract: An oil state detection apparatus detects the amount of degradation substances contained in oil. The oil state detection apparatus includes a first oscillation circuit including a coil 1 and a capacitor 2, and a first detection device. Either one of the coil 1 or the capacitor 2 is configured to be immersed in oil. The first detection device is configured to detect the oscillatory frequency of the oscillation circuit.

Abstract: Provided is a liquid sensor that can more accurately detect the state of a liquid. The liquid sensor includes a light emitting element, an optical waveguide, a light receiving element, and a detection circuit. The light receiving element is configured to receive light that was emitted by the light emitting element and passed through the optical waveguide. The detection circuit is configured to detect output of the light receiving element. The optical waveguide includes a first pillar portion that extends straight and a second pillar portion that extends straight. The second pillar portion is provided at a position opposing the first pillar portion. A space for liquid is formed between the first pillar portion and the second pillar portion. The first pillar portion includes a first end surface that faces the light emitting element, and a second end surface that is tilted relative to the first end surface and reflects light toward the second pillar portion.

Abstract: Provided is a liquid sensor capable of relatively accurately detecting the liquid level even if vibration or the like occurs. The liquid sensor is configured to detect a liquid level in a state in which at least a portion of the liquid sensor is immersed in liquid. This liquid sensor includes a substrate. The substrate is provided with a hole. An inner circumferential surface of the substrate is formed around the hole. A first electrode and a second electrode facing the first electrode are formed on the inner circumferential surface. The liquid sensor further includes a detection circuit. The detection circuit is configured to detect capacitance between the first and second electrodes.

Abstract: Provided is a liquid sensor that can more accurately detect the state of a liquid. The liquid sensor includes a light emitting element, an optical waveguide, a light receiving element, and a detection circuit. The light receiving element is configured to receive light that was emitted by the light emitting element and passed through the optical waveguide. The detection circuit is configured to detect output of the light receiving element. The optical waveguide includes a first pillar portion that extends straight and a second pillar portion that extends straight. The second pillar portion is provided at a position opposing the first pillar portion. A space for liquid is formed between the first pillar portion and the second pillar portion. The first pillar portion includes a first end surface that faces the light emitting element, and a second end surface that is tilted relative to the first end surface and reflects light toward the second pillar portion.

Abstract: Provided is a liquid sensor or the like that is relatively easy to manufacture. The liquid sensor includes a light emitting element, an optical waveguide, a light receiving element, and a detection circuit. The optical waveguide includes a first pillar portion, a first metal plate, a second pillar portion, and a second metal plate. The first metal plate is embedded in the first pillar portion. The second pillar portion is provided at a position opposing the first pillar portion. The second metal plate is embedded in the second pillar portion. A space for liquid is formed between the first pillar portion and the second pillar portion. The first pillar portion includes a first end surface that faces the light emitting element. The first metal plate includes a first reflecting portion that is tilted relative to the first end surface and reflects light toward the second pillar portion. The second pillar portion includes a second end surface that faces the light receiving element.

Abstract: Provided is a liquid sensor capable of relatively accurately detecting the liquid level even if vibration or the like occurs. The liquid sensor is configured to detect a liquid level in a state in which at least a portion of the liquid sensor is immersed in liquid. This liquid sensor includes a substrate. The substrate is provided with a hole. An inner circumferential surface of the substrate is formed around the hole. A first electrode and a second electrode facing the first electrode are formed on the inner circumferential surface. The liquid sensor further includes a detection circuit. The detection circuit is configured to detect capacitance between the first and second electrodes.

Abstract: The present invention intends to provide a liquid sensor device that achieves both the improvement of durability and the improvement of property determination accuracy. The liquid sensor device includes: an electrode pair 22 that is formed on a sensor board 2 and covered by an insulating protective film 201; a resistance measurement part 302 that supplies AC current to the electrode pair 22 to measure the resistance value of oil 4; a parasitic capacitance storage part 304 that holds the parasitic capacitance Cs of the electrode pair 22; and a property determination part 313 that, on the basis of the resistance value R1 and the parasitic capacitance Cs, determines the deterioration of the oil 4.

Abstract: An oil condition determination system includes a resistance value measurement unit and a determination unit. The resistance value measurement unit applies a measurement voltage between a pair of measurement electrodes in contact with oil to measure a resistance value of the oil. The determination unit determines, when a change tendency of the resistance value of the oil is reversed, that condition of the oil is changed.

Abstract: A method for producing a high frequency circuit board includes forming an antenna pattern on an upper surface of the provisional substrate. The method includes performing hot-press in a state where a thermoplastic resin and a provisional conductor are stacked on the upper surface of the provisional substrate, to form a first dielectric layer portion covering the antenna pattern. The method includes removing the provisional conductor and shaving the first dielectric layer portion to form a cavity to house an electronic component. The method includes mounting the electronic component on the antenna pattern in the cavity. The method includes performing hot-press in a state where a thermosetting resin and a ground conductor are stacked at an opening side of the cavity in the first dielectric layer portion, to form a second dielectric layer portion to embed the electronic component in the cavity. The method includes removing the provisional substrate.

Abstract: A method for producing a high frequency circuit board includes forming an antenna pattern on an upper surface of the provisional substrate. The method includes performing hot-press in a state where a thermoplastic resin and a provisional conductor are stacked on the upper surface of the provisional substrate, to form a first dielectric layer portion covering the antenna pattern. The method includes removing the provisional conductor and shaving the first dielectric layer portion to form a cavity to house an electronic component. The method includes mounting the electronic component on the antenna pattern in the cavity. The method includes performing hot-press in a state where a thermosetting resin and a ground conductor are stacked at an opening side of the cavity in the first dielectric layer portion, to form a second dielectric layer portion to embed the electronic component in the cavity. The method includes removing the provisional substrate.

Abstract: The present invention intends to provide a liquid sensor device that achieves both the improvement of durability and the improvement of property determination accuracy. The liquid sensor device includes: an electrode pair 22 that is formed on a sensor board 2 and covered by an insulating protective film 201; a resistance measurement part 302 that supplies AC current to the electrode pair 22 to measure the resistance value of oil 4; a parasitic capacitance storage part 304 that holds the parasitic capacitance Cs of the electrode pair 22; and a property determination part 313 that, on the basis of the resistance value R1 and the parasitic capacitance Cs, determines the deterioration of the oil 4.

Abstract: [Object] To improve the directional characteristics of a planar antenna for a milliwave band as well as widening a bandwidth. [Means for Settlement] A feed line 13 has a main feed line 21, two sub-feed lines 22, and a distributor S2 adapted to branch the main feed line 21 into the two sub-feed lines 22. The distributor S2 includes: two outer edges 30L and 30R formed as curved lines connecting both side edges 21L and 21R of the main feed line 21 to first edges 221 of the sub-feed lines 22; and an inner edge 31 connecting second edges 222 of the sub-feed lines 22 to each other, in which the inner edge 31 is configured to include two inner curved lines 31L and 31R that are convex in mutual directions, and has a pointed shape that is concave toward the main feed line 21 side.

Abstract: Provided is a distributor capable of reducing insertion loss while suppressing a ratio in power distribution among output lines from being changed. The distributor 4 is a distributor that is connected with an input line Lin and output lines Lo1 to Lo3 respectively formed on a dielectric substrate 10 as microstrip lines, and distributes to the output lines Lo1 to Lo3 high frequency power fed from a feeding point to a branching point through the input line Lin. In addition, the distributor 4 is configured to include a stub area 42 that is formed in the input line Lin, is separated from the branching point 41, and has a rectangular shape wider than line widths of a first area La and a second area Lb of the input line Lin.

Abstract: In an antenna, an antenna element interval is reduced without depending on an interval between converters, to widen the range of a phase folding angle to widen a detection angle range. The antenna includes a first antenna element including a feeder line extending from a first converter and a plurality of radiating elements. A second antenna element includes a feeder line extending from a second converter aligned together with the first converter and a plurality of radiating elements. The first and second antenna elements respectively include, at partial line portions of the feeder lines which extend from the converters to closest radiating elements, bend portions which are bent in directions which the bend portions come close to each other. The partial line portions of the first and second antenna elements are disposed so as to be linearly symmetrical about a virtual line.

Abstract: To provide a microstrip antenna that can radiate electromagnetic waves in two or more different directions while suppressing an increase in manufacturing cost. The microstrip antenna is configured to include: a dielectric substrate 10 that is adapted to be of a folded flat plate shape; two or more radiating patterns 2 for radiating electromagnetic waves; and a connecting pattern 3 for mutually connecting the radiating patterns 2 and feeding electricity from a common feeding point 4 to each of the radiating patterns 2. The radiating patterns 2 and connecting pattern 3 are respectively adapted as microstrip lines formed on the dielectric substrate 10, and the dielectric substrate 10 is folded such that the connecting pattern 3 intersects with a ridge line 5, and has two or more radiating surfaces 10a to 10c of which normal directions are mutually different.

Abstract: An antenna device according to an embodiment includes a dielectric substrate, a housing, and an interference prevention unit. On the top surface side of the dielectric substrate, a plurality of antennas is formed, and on the bottom surface side, a ground is formed, each as a conductive thin film pattern, respectively. The housing is formed of a conductive material, and formed to have a shape configured to function as a waveguide, and the top surface side of the housing is bonded to the bottom surface side of the dielectric substrate. The interference prevention unit is formed between the neighboring antennas to include at least a groove provided on the top surface side of the housing and a slit provided on the ground in the portion corresponding to the groove.

Abstract: [Object] To improve the directional characteristics of a planar antenna for a milliwave band as well as widening a bandwidth. [Means for Settlement] A feed line 13 has a main feed line 21, two sub-feed lines 22, and a distributor S2 adapted to branch the main feed line 21 into the two sub-feed lines 22. The distributor S2 includes: two outer edges 30L and 30R formed as curved lines connecting both side edges 21L and 21R of the main feed line 21 to first edges 221 of the sub-feed lines 22; and an inner edge 31 connecting second edges 222 of the sub-feed lines 22 to each other, in which the inner edge 31 is configured to include two inner curved lines 31L and 31R that are convex in mutual directions, and has a pointed shape that is concave toward the main feed line 21 side.