A frequency selective surface (FSS) having periodicity between one eighth and one quarter of an operational wavelength of the FSS and a low profile. The FSS has multiple pattern elements which are used to produce multiple transmission poles, and in some embodiments multiple transmission zeros. The transmission poles and transmission zeros are in the Ka and Ku bands, making the FSS applicable to 5G application. The transmission poles and transmission zeros also have high angular stability an oblique incident angle as high as 60°, as well as polarization insensitivity.

A measuring device, configured to detect a process variable in a container, is provided, the measuring device including: electronic circuitry with a housing and a sealing abutting the housing, the measuring device being further configured to be arranged in a container opening, and when the measuring device is arranged in the container opening: the sealing is configured to seal the container opening, and the electronic circuitry is arranged below a geometric plane of the sealing. A container including a container opening and the measuring device is also provided.

Various examples are provided for flat lens antennas and their operation. In one example, among others, an antenna includes electrically thin (W<<λhigh), highly conducting, TEM mode antenna arms fed at a first end by a balun. The TEM mode antenna arms can be embedded in a spatially varied anisotropic dielectric material. A separation between the TEM mode antenna arms can increase from the first end to a second end where the TEM mode antenna arms transition to resistive card (Rcard) terminations when the TEM mode antenna arms are separated by a distance Hr, where a ratio of Hr to a height (H) of the antenna is in a range from about 0.2 to about 0.8.

Various examples are provided for flat lens antennas and their operation. In one example, among others, an antenna includes electrically thin (W<<λhigh), highly conducting, TEM mode antenna arms fed at a first end by a balun. The TEM mode antenna arms can be embedded in a spatially varied anisotropic dielectric material. A separation between the TEM mode antenna arms can increase from the first end to a second end where the TEM mode antenna arms transition to resistive card (Rcard) terminations when the TEM mode antenna arms are separated by a distance Hr, where a ratio of Hr to a height (H) of the antenna is in a range from about 0.2 to about 0.8.

A radar antenna for a fill level measurement device is provided that includes at least one carrier plate and at least two antenna elements that are arranged on the carrier plate and are configured to transmit and/or to receive a radar signal, wherein each of the antenna elements includes a waveguide configured to direct the radar signal, wherein an interior volume of each waveguide is at least partially filled with a dielectric, the antenna elements being arranged at a distance from one another that is less than or equal to a wavelength of the radar signal.

A radar antenna for a fill level measurement device is provided that includes at least one carrier plate and at least two antenna elements that are arranged on the carrier plate and are configured to transmit and/or to receive a radar signal, wherein each of the antenna elements includes a waveguide configured to direct the radar signal, wherein an interior volume of each waveguide is at least partially filled with a dielectric, the antenna elements being arranged at a distance from one another that is less than or equal to a wavelength of the radar signal.

The present invention provides an antenna comprising: a radiation unit that is formed on a substrate; a waveguide that propagates therein radio waves radiated from the radiation unit and radiates the radio waves as a beam; and a dielectric lens that is arranged in an opening of the waveguide and has an incident plane facing the radiation unit and a radiation plane radiating radio waves entered from the incident plane. The radiation plane of the dielectric lens has a plane orientation different from a flat plane perpendicular to the radiation direction of the beam.

The present invention provides an antenna comprising: a radiation unit that is formed on a substrate; a waveguide that propagates therein radio waves radiated from the radiation unit and radiates the radio waves as a beam; and a dielectric lens that is arranged in an opening of the waveguide and has an incident plane facing the radiation unit and a radiation plane radiating radio waves entered from the incident plane. The radiation plane of the dielectric lens has a plane orientation different from a flat plane perpendicular to the radiation direction of the beam.

A frequency selective surface (FSS) having periodicity between one eighth and one quarter of an operational wavelength of the FSS and a low profile. The FSS has multiple pattern elements which are used to produce multiple transmission poles, and in some embodiments multiple transmission zeros. The transmission poles and transmission zeros are in the Ka and Ku bands, making the FSS applicable to 5G application. The transmission poles and transmission zeros also have high angular stability an oblique incident angle as high as 60°, as well as polarization insensitivity.

Aspects of the subject disclosure may include a generator that facilitates generation of an electromagnetic wave, a core, and a waveguide that facilitates guiding the electromagnetic wave towards the core to induce a second electromagnetic wave that propagates along the core. The core and/or the waveguide can be configured to reduce radiation loss of the second electromagnetic wave, propagation loss of the second electromagnetic wave, or a combination thereof. Other embodiments are disclosed.