An electromagnetic energy absorber comprising a thin electrically-conductive ground plane as a base. Dielectric layers are positioned over the ground plane and high impedance surface (HIS) as a top layer. The impedance layer can be formed by loading the lumped resistor to a metallic grating like an FSS (Frequency Selective Surface). An air-spacer between the substrates has replaced the problem of the large electrical thickness of the substrate with effective permittivity. Metamaterial structures enable control over the resonant frequencies, and performance is enhanced over a broad frequency band. In addition, two broadband reflective-type linear to orthogonal polarization converters are disclosed that provide improved bandwidth and angular stability performance.

A wellbore servicing tool. The wellbore servicing tool comprises a tool body, an electromagnetic transmitter coupled to the tool body, an electromagnetic receiver coupled to the tool body and spaced apart from the electromagnetic transmitter, wherein a portion of the tool body between the electromagnetic transmitter and the electromagnetic receiver defines a direct signal path between the electromagnetic transmitter and the electromagnetic receiver, and an absorbing material coupled to the tool body in the direct signal path between the electromagnetic transmitter and the electromagnetic receiver, proximate to the electromagnetic receiver.

A radio frequency (RF) test hat. The RF test hat may comprise: a cylinder having forward and aft ends, end cap, arm and strap assembly, first and second absorber materials, a receiving antenna, and lens. The end cap may couple to the forward end of the cylinder. The arm and strap assembly may hingedly couple to the aft end of the cylinder and may be configured to mount the RF test hat onto a pod or transmitting antenna. The first absorber material may be located within the forward end of the cylinder. The second absorber material may be located near the aft end of the cylinder. The receiving antenna, which may be disposed within the first absorber material, may measure the intensity of a beam of electromagnetic radiation. The lens, which may be located within the middle portion of the cylinder, may spread the beam across a larger surface area of the first absorber material.

A radio frequency (RF) test hat. The RF test hat may comprise: a body having a substantially rectangular portion with open forward and aft ends, an end cap, arm and strap assembly, absorber material, a receiving antenna, lens, and upper and lower mesh screens. The end cap may couple to the open forward end of the body. The arm and strap assembly may hingedly couple to the open aft end of the body. The absorber material may be within the end cap. The receiving antenna may be disposed within the first absorber material and may measure the intensity of a beam of electromagnetic radiation. The lens may be located within the middle portion of the body and may spread the beam across a larger surface area of the absorber material. The upper and lower mesh screens may be disposed between the end cap and lens and may comprise openings that are substantially hexagonal in shape.

The disclosure provides an integrated wave-absorbing and wave-transparent apparatus and a radome. The integrated wave-absorbing and wave-transparent apparatus includes: a wave-transparent structure, including a first substrate and a metal patch unit located on opposite surfaces of the substrate; and a wave-absorbing structure, disposed on the wave-transparent structure and including a first wave-absorbing unit and a second wave-absorbing unit that are perpendicular to each other, where the first wave-absorbing unit and the second wave-absorbing unit each includes: a second substrate; and a plurality of metal sections and a plurality of stop-bands that are located on surfaces of the second substrate, where the plurality of metal sections and the plurality of stop-bands are connected alternately to form an absorption ring, and the metal patch unit is configured to be perpendicular to each of an absorption ring of the first wave-absorbing unit and an absorption ring of the second wave-absorbing unit.

A radio frequency (RF) test hat. The RF test hat may comprise: a cylinder having forward and aft ends, end cap, arm and strap assembly, first and second absorber materials, a receiving antenna, and lens. The end cap may couple to the forward end of the cylinder. The arm and strap assembly may hingedly couple to the aft end of the cylinder and may be configured to mount the RF test hat onto a pod or transmitting antenna. The first absorber material may be located within the forward end of the cylinder. The second absorber material may be located near the aft end of the cylinder. The receiving antenna, which may be disposed within the first absorber material, may measure the intensity of a beam of electromagnetic radiation. The lens, which may be located within the middle portion of the cylinder, may spread the beam across a larger surface area of the first absorber material.

An RF test hat. The RF test hat may comprise: a body having a substantially rectangular portion with open forward and aft ends, an end cap, arm and strap assembly, absorber material, a receiving antenna, lens, and upper and lower mesh screens. The end cap may couple to the open forward end of the body. The arm and strap assembly may hingedly couple to the open aft end of the body. The absorber material may be within the end cap. The receiving antenna may be disposed within the first absorber material and may measure the intensity of a beam of electromagnetic radiation. The lens may be located within the middle portion of the body and may spread the beam across a larger surface area of the absorber material. The upper and lower mesh screens may be disposed between the end cap and lens and may comprise openings that are substantially hexagonal in shape.

In some implementations, a metamaterial absorber (MMA) is configured to absorb a particular range of electromagnetic radiation. The MMA includes a first metal or semiconductor material; a dielectric material disposed on the first metal or semiconductor material; and a second metal material disposed on the dielectric material. A length dimension associated with the MMA is less than or equal to 200 micrometers (μm), a width dimension associated with the MMA is less than or equal to 200 μm, and a thickness dimension associated with the MMA is less than or equal to 8 μm.

An electronic device disposed on a door frame includes a back plate attached to the door frame, a housing coupled to the back plate, a first antenna that transmits or receives a signal having a first wavelength with an external electronic device, a second antenna that is disposed closer to the back plate than the first antenna and that transmits or receives a signal having the first wavelength with the external electronic device, an electric-wave blocking member that is disposed between the back plate and the second antenna and that blocks a signal reflected by the door frame, and at least one processor operatively connected with the first antenna and the second antenna. The first antenna and the second antenna are disposed inside the housing, and an antenna pattern of the second antenna is different from an antenna pattern of the first antenna.

A method includes obtaining a base housing for electronic components. The base housing attenuates radiation entering the base housing by a base amount. An inner volume of the base housing defined by an inner surface of the base housing experiences attenuated radiation. The method also includes affixing one or more inserts to the inner surface of the base housing to further attenuate the attenuated radiation in corresponding one or more areas of the inner volume.