An antenna device includes: a pair of first elements that are arranged on a first plane; and a pair of second elements that are arranged on a second plane parallel to the first plane such that a polarized wave direction of the pair of second elements is orthogonal to that of the pair of first elements. Each element of the pair of first elements and the pair of second elements includes a portion that acts as a self-similarity antenna or an antenna that acts based on similar operating principle to the self-similarity antenna. In one embodiment, each element of the pair of first elements and the pair of second elements includes two arms that extend in a direction away from each other from a proximal end portion to which a feed point is connectable.

A waveguide antenna (200) is disclosed, comprising: a first plurality (220) of slots (222,224), for producing a beam having a first radiation pattern (301) at a first resonant frequency (f1); and a second plurality (230) of slots (232, 234), for producing a beam having a second radiation pattern (302) at a second resonant frequency (f2). A method of operation of the waveguide antenna (200) is also disclosed, comprising: operating the transceiver at a first frequency (f1) to detect objects in a first field of view; and operating the transceiver at a second frequency (fa) to detect objects in a second field of view

An antenna structure according to an embodiment of the present disclosure includes a dielectric layer, and an antenna unit disposed on a top surface of the dielectric layer. The antenna unit includes a radiator including convex portions and concave portions, a transmission line including a first transmission line and a second transmission line that extend in different directions to be connected to the radiator, and a parasitic element disposed to be adjacent to the transmission line and electrically and physically separated from the transmission line and the radiator. A length of the parasitic element in an extension direction of the transmission line is from 45% to 70% of a half wavelength (λ/2) at a maximum resonance frequency from the antenna unit.

Dual-mode RFID devices are provided with an integrated dual-mode RFID strap including either a UHF/HF dual-mode RFID chip or the combination of a UHF RFID chip and an HF RFID chip. An HF antenna and a UHF antenna are both coupled to the integrated dual-mode RFID strap, with the UHF antenna being formed by an approach other than etching, such as a cutting or printing operation, thereby reducing the cost to manufacture the device. If a pair of chips is employed, one of the chips may have a greater thickness than the other chip, which allows for the thicker chip to be incorporated into the device after the thinner chip without requiring a minimum separation between the two chips due to the size of a thermode used to secure the chips. Additionally, the first chip may be tested before securing the second chip, thereby limiting the cost of a rejected device.

A parasitically-coupled dual-band patch antenna is described. The antenna includes an inner conductor having one or more feed holes. The antenna also includes an outer conductor surrounding the inner conductor in a radial direction. The antenna further includes one or more feeds each having a vertical portion that passes through the feed holes and a horizontal portion that extends in an outward direction from the feed holes toward the outer conductor. The feeds are conductively connected to the outer conductor. The horizontal portion of each of the feeds is separated from and is conductively disconnected from a top surface of the inner conductor.

An antenna device includes a first conductor plate including a first end portion and a second end portion, the first conductor plate being provided with a first feeding portion between the first end portion and the second end portion, a second conductor plate including a third end portion connected to the first feeding portion, a fourth end portion located at a position away from the first conductor plate, and a plate surface of which width in a direction parallel to the first conductor plate increases with a distance from the third end portion toward the fourth end portion, and a third conductor plate including a fifth end portion capacitively coupling with the fourth end portion, a sixth end portion connected, on a same side as the first end portion with respect to the first feeding portion, to the first conductor plate, and a counter portion opposite the plate surface.

An antenna device includes a first conductor plate including a first end portion and a second end portion, the first conductor plate being provided with a first feeding portion between the first end portion and the second end portion, a second conductor plate including a third end portion connected to the first feeding portion, a fourth end portion located at a position away from the first conductor plate, and a plate surface of which width in a direction parallel to the first conductor plate increases with a distance from the third end portion toward the fourth end portion, and a third conductor plate including a fifth end portion capacitively coupling with the fourth end portion, a sixth end portion connected, on a same side as the first end portion with respect to the first feeding portion, to the first conductor plate, and a counter portion opposite the plate surface.

A radiofrequency transmission/reception device includes a first and a second conductive wire element, a first far-field transmission/reception chip and a second near-field transmission/reception chip. The first and the second wire element combine with the characteristic impedance of the second transmission/reception chip in order to form a coupling device associated with the first transmission/reception chip at the operating frequency of the first chip. The first and the second wire element combine with the characteristic impedance of the first transmission/reception chip in order to form a coupling device associated with the second transmission/reception chip at the operating frequency of the second chip.

A radiofrequency transmission/reception device includes a first and a second conductive wire element, a first far-field transmission/reception chip and a second near-field transmission/reception chip. The first and the second wire element combine with the characteristic impedance of the second transmission/reception chip in order to form a coupling device associated with the first transmission/reception chip at the operating frequency of the first chip. The first and the second wire element combine with the characteristic impedance of the first transmission/reception chip in order to form a coupling device associated with the second transmission/reception chip at the operating frequency of the second chip.

A multi-mode microwave waveguide blade sensing system includes a transceiver, a waveguide, and a probe sensor. The transceiver generates a microwave energy signal having a first waveguide mode and a different second waveguide mode. The waveguide includes a first end that receives the microwave energy signal. The probe sensor includes a proximate end that receives the microwave energy signal from the transceiver and a distal end including an aperture that outputs the microwave energy signal. The probe sensor directs the microwave energy signal at a first direction based on the first waveguide mode and a different second direction different based on the second waveguide mode. The probe sensor receives different levels of reflected microwave energy based at least in part on a location at which the at least one microwave energy signal is reflected from the machine.