An impedance matching film 10 includes a mixture containing indium oxide and tin oxide and being a main component of the impedance matching film, the mixture having an amorphous structure. The impedance matching film 10 for impedance matching has a Hall mobility of 5 cm.sup.2/(V.Math.s) or more. The impedance matching film 10 has a thickness of 16 nm or more and less than 100 nm.

The disclosure discloses an absorbing metamaterial, including a plurality of metamaterial units that are periodically arranged, where the metamaterial unit includes: a first loop disposed on a first plane; and a second loop disposed on a second plane, where the first plane is perpendicular to the second plane, so that the first loop and the second loop are orthogonal. According to the foregoing technical solution in the disclosure, wave absorption in a large angle range can be implemented while ensuring wideband wave absorption.

An electromagnetic wave absorber and an electromagnetic wave anechoic room using the absorbers. The electromagnetic wave absorber has improved electromagnetic wave absorption characteristics at high frequencies in spite of having a hollow structure. The electromagnetic wave absorber includes a hollow shell with a bottom that is a rectangle. A part of a surface of the hollow shell and an outer face of a planar extension lie in planes that are not parallel to any side of the rectangle. At least the plane that is not parallel to any side of the rectangle is included in a surface of an electromagnetic wave absorption member.

A radar sensor includes: a radar antenna, a radar lens and a funnel element between the radar antenna and the radar lens. The funnel element includes a material which absorbs the radar radiation emitted by the radar antenna.

A base station antenna may include a radiation element configured to operate in a predetermined frequency band; and an absorbing device arranged above the radiation element and configured to absorb electromagnetic radiation of the predetermined frequency band. The absorbing device may be made of a metamaterial.

An antenna includes a reflector having a front side that includes a first region and a second region that does not overlap the first region, a first column of radiating elements element that is located on the front side of the reflector and is configured to emit electromagnetic radiation within a first frequency band, the first column of radiating elements mounted to extend forwardly from the first region, and a reflection reducing component mounted forwardly of the second region, wherein the reflection reducing component is configured such that electromagnetic radiation within the first frequency band that is reflected by the reflection reducing component is weaker than electromagnetic radiation within the first frequency band that is reflected by the first region of the reflector.

A method for the dynamic configuration of a test chamber for wireless communications is provided. The method includes identifying a current test project to be performed on a test device. The test device is disposed within a test chamber for evaluating one or more interactions of the test device with a wireless communication network. The method also includes determining a test configuration of a wireless connection interface of the test chamber based on the identified current test project and then sending a control signal to the wireless connection interface to set the wireless connection interface to the test configuration. In operation, the test configuration of the wireless connection interface controls which of a plurality of wireless signals of the wireless communication network are emitted within an interior the test chamber.

An apparatus for reducing interference in an antenna from a radio wave is provided. A method for blocking an electromagnetic wave signal port is used. A WiFi antenna is enclosed by using an electromagnetic wave blocking material (such as an aluminum metal mesh) to form an enclosure surrounding the WiFi antenna. The enclosure is provided with one or more electromagnetic wave signal ports, to form an electromagnetic wave selection enclosure (wave selection enclosure). When a wavelength satisfies a requirement, an electromagnetic wave having a signal with sufficient strength, or a signal in an appropriate direction with insufficient strength (for example, entering the signal port in a route closer to a linear route) is allowed to enter the enclosure and communicate with the antenna, reducing or eliminating mainly interference in the antenna in the enclosure from another co-frequency electromagnetic wave outside the enclosure.

A radio frequency (RF) aperture includes an interface printed circuit board. An array of electrically conductive tapered projections have bases disposed on a front side of the interface printed circuit board and extend away from the front side of the interface printed circuit board. Chip baluns are mounted on the back side of the interface printed circuit board. Each chip balun has a balanced port electrically connected with two neighboring electrically conductive tapered projections via electrical feedthroughs passing through the interface printed circuit board. Each chip balun further has an unbalanced port, and RF circuitry disposed at the back side of the interface printed circuit board is electrically connected with the unbalanced ports of the chip baluns. The electrically conductive tapered projections include dielectric tapered projections and an electrically conductive layer disposed on an inner or outer surface of the dielectric tapered projections.

RF-absorber assemblies for assisting PIM hunting at cellular base station antennas. An RF-absorber panel section includes a non-absorbing spacer layer adjacent to an antenna under evaluation. An RF-absorbing layer is positioned adjacent to the non-absorbing spacer layer. A low-PIM RF-shield layer is positioned adjacent to the RF-absorbing layer, so that the RF-absorbing layer is positioned between the RF-shield layer and the non-absorbing spacer layer. RF-absorber panel assembly kits include RF-absorber panel sections that removably attach to each other and to an assembly cover, which removably attaches over a panel antenna. A cylindrical assembly for a multi-directional antennas includes tapered RF-absorber sections within a cylindrical RF-absorber. An iris allows directional PIM hunting with the cylindrical RF-absorber. A PIM hunting procedure utilizes a full-perimeter RF panel assembly for directional PIM hunting. A directional RF-absorber panel assembly includes front and rear RF-absorber panel assemblies and lateral RF-shield blankets.