Provided is a radio wave absorber including: a support; a first radio wave absorption layer having a flat plate shape that is disposed on a surface of the support and includes a radio wave absorption material and a binder; and second radio wave absorption layers that are erected on a surface of the first radio wave absorption layer, include a radio wave absorption material and a binder, and are conical protrusions having bottom surfaces of which outer peripheral portions are in contact with each other, in which a distance between apexes of the conical protrusions adjacent to each other is 0.5 mm to .sup.a mm, in a case where a wavelength of a radio wave to be absorbed is set as .sup.a mm, and a manufacturing method of a radio wave absorber.

In one embodiment, an antenna assembly includes a reflector antenna whose aperture is covered by a radome. The radome has a principle plane corresponding to the azimuth axis of the antenna. The radome has a bulk material and a pair of absorbers made of a radio-frequency (RF)-absorbent material different from the bulk material. The pair of absorbers are arranged symmetrically along the principle plane and about the center of the radome. The pair of absorbers are located near the perimeter of the radome and are at least partially embedded in the bulk material. The pair of absorbers cover from 4%-8% of the total aperture area of the antenna.

An antenna assembly may include an antenna element, a radome structure disposed proximate to the antenna element and including a plurality of plasma elements, a driver circuit operably coupled to the plasma elements to selectively ionize individual ones of the plasma elements, and a controller. The controller may be operably coupled to the driver circuit to provide control of plasma density of the individual ones of the plasma elements. The plasma elements may include respective enclosures. At least some of the enclosures may have at least two peripheral edge surfaces substantially fully contacted by corresponding peripheral edge surfaces of adjacent enclosures at at least one section along a longitudinal length thereof.

A radar apparatus includes: a receiving unit including plural receiving antennas including an antenna element, and configured to receive incoming waves whose arrival directions are known; and a calculating unit configured to calculate a correction value for correcting an error component included in a received signal of the incoming waves received by the receiving unit based on the received signal, the correction value being depending on an azimuth of the antenna element.

Disclosed are multiple-input, multiple-output (MIMO) antenna systems with high gain having an impedance bandwidth greater than 1 GHz and high side-lobe rejection. Suitable systems are configurable to have a radar lens with, for example, an 81 antenna array. Additionally, beam steering architecture that concentrates radiated energy through a dielectric lens to achieve a narrow high-gain beam.

A method to mitigate an antenna multipath, Rayleigh fading effect. The method includes coupling an antenna on top of a structure, wherein the structure is covered by a radio frequency (RF) radiation absorbing layer, wherein the structure has a shape such that any reflecting surface of the structure is perpendicular to an incoming RF signal. The method also includes directing the incoming RF signal towards the structure, wherein undesired direct or reflected RF signals are either absorbed by the RF radiation absorbing layer or deflected back to a source of the RF signal, thereby avoiding interference of the undesired RF signal with a desired RF signal aimed at the antenna.

Embodiments of the present disclosure provide methods, apparatuses, devices and systems related to the implementation of a multi-layer printed circuit board (PCB) radio-frequency antenna featuring, a printed radiating element coupled to an absorbing element embedded in the PCB. The embedded element is configured within the PCB layers to prevent out-of-phase reflections to the bore-sight direction.

An electromagnetic (EM) probe for monitoring one or more biological tissues. The EM probe comprises a cup shaped cavity having an opening and an interior volume, a circumferential flange formed substantially around the cup shaped cavity, in proximity to the opening, at least one layer of a material, for absorbing electromagnetic radiation, applied over at least one of a portion of the circumferential flange and a portion of the outer surface of the cup shaped cavity, and at least one EM radiation element which performs at least one of emitting and capturing EM radiation via the interior volume.

A method (400) for positioning a first and a second radio antenna comprising the steps of configuring (SI) the first antenna to have a main lobe L1 and configuring (52) the second antenna to be a directive antenna having a main lobe L2. The method also comprising the steps of transmitting (S3) a first alignment signal from the first antenna to the second antenna and positioning (S4) the second antenna based on the received first alignment signal, as well as reconfiguring (S5) the first antenna to be a directive antenna having an antenna main lobe L3, the antenna main lobe L3 having a more narrow main lobe width than the antenna main lobe L1. The method provides a systematic approach to finding optimum antenna positions and corresponding main lobe directions which is especially suited for aligning directive radio antennas in NLOS communication scenarios.

The present disclosure provides a radar apparatus and a method of correcting an error of the radar apparatus. According to the present disclosure a first transmitting antenna group and a first receiving antenna group are constituted by elongating some of a plurality of transmitting antennas and a plurality of receiving antennas in a first direction of vertical directions, a second transmitting antenna group and a second receiving antenna group are constituted by elongating the other antennas in a second direction opposite to the first direction, and one or more of transmitting antennas that transmit transmission signals and one or more of receiving antennas that receive reflection signals are included in different groups, thereby being able to measure elevation information of an object and correct a mounting position of the radar apparatus on the basis of the information.