Abstract: An antenna device includes first and second radiating elements, a first coil coupled to the first radiating element or a feeding circuit, a second coil coupled to the second radiating element and coupled to the first coil via an electromagnetic field, and an inductor. The first and second radiating elements are coupled to each other via an electric field. The harmonic resonant frequency of a resonance circuit defined by a transformer defined by the first coil and the second coil, the inductor, and the second radiating element exists within a communication frequency range. The harmonic resonant frequency is a (2n+1)th harmonic frequency, where n is an integer equal to or greater than 1.

Abstract: An antenna device includes a feeder circuit, a patch antenna, an antenna, a first coil connected between the feeder circuit and the patch antenna, and a second coil connected to the antenna and magnetically coupled to the first coil. The patch antenna resonates in a first frequency range in a first direction and in a second frequency range in a second direction. The antenna resonates in a third frequency range. A first center frequency refers to the center frequency of the first frequency range, a second center frequency refers to the center frequency of the second frequency range, a third center frequency refers to the center frequency of the third frequency range, and an absolute value of a difference between the first center frequency and the third center frequency is less than an absolute value of a difference between the second center frequency and the third center frequency.

Abstract: An antenna device includes a first radiating element, a second radiating element having lower radiation efficiency than the first radiating element, a coupling element including first and second coils that are electromagnetically coupled to each other, and first and second phase adjusting elements. The first and second phase adjusting elements induce, at a resonant frequency of the second radiating element, a predetermined proportion of current flowing through the second radiating element to the first radiating element.

Abstract: An antenna device includes first and second radiating elements, a first coil coupled to the first radiating element or a feeding circuit, a second coil coupled to the second radiating element and coupled to the first coil via an electromagnetic field, and an inductor. The first and second radiating elements are coupled to each other via an electric field. The harmonic resonant frequency of a resonance circuit defined by a transformer defined by the first coil and the second coil, the inductor, and the second radiating element exists within a communication frequency range. The harmonic resonant frequency is a (2n+1)th harmonic frequency, where n is an integer equal to or greater than 1.

Abstract: An antenna unit includes a coupling element including first and second coils, a feeding radiating element, and a parasitic radiating element. A series circuit including the first coil and a feeder circuit is connected to the feeding radiating element, and the parasitic radiating element is connected to the second coil. A distance between open ends of the parasitic radiating element and a short portion of the feeding radiating element is shorter than a distance between open ends of the parasitic radiating element and a long portion the feeding radiating element. The antenna unit is an antenna for a first frequency band with fundamental wave resonance of the long portion and fundamental wave resonance of the parasitic radiating element, and a second frequency band with higher-order resonance of the parasitic radiating element and resonance of the short portion, the second frequency band being higher than the first frequency band.

Abstract: An antenna apparatus includes first and second antennas. First and second radiating elements include parallel extending portions. A first coil is connected between the first radiating element and a first feed circuit connection portion. A second coil is connected between the second radiating element and a ground conductor. The first and second coils are coupled to each other in additive polarity. A phase adjustment circuit adjusts a phase difference between currents respectively flowing through the first and second radiating elements to greater than or equal to about 90 degrees and less than about 180 degrees in a communication frequency band of the second antenna. Where a frequency of a fundamental of the first radiating element is f1 and a frequency of a fundamental of the second radiating element is f2, f1>f2, and 3f2?f1>f1?f2 are satisfied.

Abstract: An antenna device includes a circuit substrate, first and second radiators each including an open end, and a coupler to electromagnetically couple the first and second radiators, the antenna device being provided in a housing of an electronic apparatus. Shield cases each including a planar conductor portion parallel or substantially parallel to a first main surface are mounted on the circuit substrate, the first radiator, the second radiator, and the shield cases are located on a side of the first main surface of the circuit substrate, and the first radiator includes a portion overlapping a first region between the multiple shield cases in plan view of the circuit substrate.

Abstract: An antenna device includes first and second radiating elements, a first coil coupled to the first radiating element or a feeding circuit, and a second coil coupled to the second radiating element and coupled to the first coil via an electromagnetic field. The first and second radiating elements are coupled to each other via an electric field. At a resonant frequency defined by the antenna coupling element and the second radiating element, the absolute value of the phase difference between a current flowing into the second radiating element due to the electromagnetic field of the first coil and the second coil and a current flowing into the second radiating element due to the electric field is equal to or less than about 90 degrees.

Abstract: An antenna device includes a radiating element, a coupling circuit, and a non-radiating resonant circuit. The coupling circuit includes first and second coupling elements, the first coupling element being connected between a feeder circuit and the radiating element, the second coupling element being coupled to the first coupling element. An end of the second coupling element is grounded, and another end of the second coupling element is connected to the non-radiating resonant circuit. A frequency characteristic of a return loss of the radiating element when seen from the feeder circuit is adjusted by a resonant frequency characteristic of the non-radiating resonant circuit.

Abstract: An antenna unit includes a coupling element including first and second coils, a feeding radiating element, and a parasitic radiating element. A series circuit including the first coil and a feeder circuit is connected to the feeding radiating element, and the parasitic radiating element is connected to the second coil. A distance between open ends of the parasitic radiating element and a short portion of the feeding radiating element is shorter than a distance between open ends of the parasitic radiating element and a long portion the feeding radiating element. The antenna unit is an antenna for a first frequency band with fundamental wave resonance of the long portion and fundamental wave resonance of the parasitic radiating element, and a second frequency band with higher-order resonance of the parasitic radiating element and resonance of the short portion, the second frequency band being higher than the first frequency band.

Abstract: An antenna device includes a first radiating element, a second radiating element having lower radiation efficiency than the first radiating element, a coupling element including first and second coils that are electromagnetically coupled to each other, and first and second phase adjusting elements. The first and second phase adjusting elements induce, at a resonant frequency of the second radiating element, a predetermined proportion of current flowing through the second radiating element to the first radiating element.

Abstract: An antenna device includes a radiating element, a coupling circuit, and a non-radiating resonant circuit. The coupling circuit includes first and second coupling elements, the first coupling element being connected between a feeder circuit and the radiating element, the second coupling element being coupled to the first coupling element. An end of the second coupling element is grounded, and another end of the second coupling element is connected to the non-radiating resonant circuit. A frequency characteristic of a return loss of the radiating element when seen from the feeder circuit is adjusted by a resonant frequency characteristic of the non-radiating resonant circuit.

Abstract: An antenna apparatus includes first and second antennas. First and second radiating elements include parallel extending portions. A first coil is connected between the first radiating element and a first feed circuit connection portion. A second coil is connected between the second radiating element and a ground conductor. The first and second coils are coupled to each other in additive polarity. A phase adjustment circuit adjusts a phase difference between currents respectively flowing through the first and second radiating elements to greater than or equal to about 90 degrees and less than about 180 degrees in a communication frequency band of the second antenna. Where a frequency of a fundamental of the first radiating element is f1 and a frequency of a fundamental of the second radiating element is f2, f1>f2, and 3f2?f1>f1?f2 are satisfied.

Abstract: A magnetic field coupling element includes conductor patterns stacked with insulating layers interposed therebetween, and interlayer connection conductors that inter-connect the conductor patterns at predetermined positions. The conductor patterns include first, second, third, and fourth conductor patterns, and the interlayer connection conductors include first and second interlayer connection conductors. The first conductor pattern, the second conductor pattern, and the first interlayer connection conductor define a first coil, and the third conductor pattern, the fourth conductor pattern, and the second interlayer connection conductor define a second coil. The first coil and the second coil are disposed in a region of less than about ? of a stacking height of a multi-layer body including the insulating layers.

Abstract: An antenna coupling element includes a first coil connected to a first radiating element and a feeder circuit and a second coil connected to a second radiating element and electromagnetically coupled to the first coil. The first and second coils have a relationship in which a direction of a magnetic field generated in the first coil when a current flows from the first coil toward the first radiating element and a direction of a magnetic field generated in the second coil when a current flows from the second coil toward the second radiating element are opposite to each other. The first and second coils are set such that a resonant frequency of a fundamental wave of the second radiating element with a transformer defined by the first coil and the second coil is lower than a resonant frequency of a fundamental wave of the first radiating element.

Abstract: An antenna device includes first and second radiating elements, a first coil coupled to the first radiating element or a feeding circuit, and a second coil coupled to the second radiating element and coupled to the first coil via an electromagnetic field. The first and second radiating elements are coupled to each other via an electric field. At a resonant frequency defined by the antenna coupling element and the second radiating element, the absolute value of the phase difference between a current flowing into the second radiating element due to the electromagnetic field of the first coil and the second coil and a current flowing into the second radiating element due to the electric field is equal to or less than about 90 degrees.

Abstract: An antenna device includes first and second radiating elements, a first coil coupled to the first radiating element or a feeding circuit, a second coil coupled to the second radiating element and coupled to the first coil via an electromagnetic field, and an inductor. The first and second radiating elements are coupled to each other via an electric field. The harmonic resonant frequency of a resonance circuit defined by a transformer defined by the first coil and the second coil, the inductor, and the second radiating element exists within a communication frequency range. The harmonic resonant frequency is a (2n+1)th harmonic frequency, where n is an integer equal to or greater than 1.

Abstract: A wireless module includes a substrate that includes a first portion, a second portion, and a first flexible portion connecting the first portion and the second portion to each other. The first portion includes a circuit element that is mounted on the first main surface and a circuit including at least the circuit element. The second portion includes a first coil connected to the circuit. The first portion and the second portion face each other. A magnetic sheet is disposed on a second main surface of the second portion, and a battery is disposed between the second main surface of the first portion and the magnetic layer.

Abstract: An antenna device includes a radiating element, a coupling circuit, and a non-radiating resonant circuit. The coupling circuit includes first and second coupling elements, the first coupling element being connected between a feeder circuit and the radiating element, the second coupling element being coupled to the first coupling element. An end of the second coupling element is grounded, and another end of the second coupling element is connected to the non-radiating resonant circuit. A frequency characteristic of a return loss of the radiating element when seen from the feeder circuit is adjusted by a resonant frequency characteristic of the non-radiating resonant circuit.

Abstract: A magnetic field coupling element includes conductor patterns stacked with insulating layers interposed therebetween, and interlayer connection conductors that inter-connect the conductor patterns at predetermined positions. The conductor patterns include first, second, third, and fourth conductor patterns, and the interlayer connection conductors include first and second interlayer connection conductors. The first conductor pattern, the second conductor pattern, and the first interlayer connection conductor define a first coil, and the third conductor pattern, the fourth conductor pattern, and the second interlayer connection conductor define a second coil. The first coil and the second coil are disposed in a region of less than about 1/3 of a stacking height of a multi-layer body including the insulating layers.