A semiconductor package includes a substrate having thereon at least an antenna layer and a ground reflector layer under the antenna layer, a radio frequency (RF) die disposed on or in the substrate, a molding compound disposed on the antenna layer of the substrate, and a frequency-selective surface (FSS) structure disposed on the molding compound. The FSS structure is a two-dimensional periodic array of metal patterns of same shape and size. The FSS structure has highly reflective characteristic.

A semiconductor package includes a substrate having thereon at least an antenna layer and a ground reflector layer under the antenna layer, a radio frequency (RF) die disposed on or in the substrate, a molding compound disposed on the antenna layer of the substrate, and a frequency-selective surface (FSS) structure disposed on the molding compound. The FSS structure is a two-dimensional periodic array of metal patterns of same shape and size. The FSS structure has highly reflective characteristic.

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 dielectric lens is disclosed comprising a center portion that extends along a cylinder having a central axis and a plurality of spoke portions that are attached to the center portion and extend to a spherical perimeter region in a radial direction from the center portion. The plurality of spoke portions includes at least a first monolithic spoke portion extending from the center portion to the spherical perimeter region and the center portion and the plurality of spoke portions define a plurality of cavity regions among the plurality of spoke portions. The center portion, the cylinder, the plurality of spoke portions, and the plurality of cavity regions are included in a gradient index (GRIN) dielectric lens having a plurality of relative permittivities that are based on a radial distance from the center portion.

A dielectric lens is disclosed comprising a center portion that extends along a cylinder having a central axis and a plurality of spoke portions that are attached to the center portion and extend to a spherical perimeter region in a radial direction from the center portion. The plurality of spoke portions includes at least a first monolithic spoke portion extending from the center portion to the spherical perimeter region and the center portion and the plurality of spoke portions define a plurality of cavity regions among the plurality of spoke portions. The center portion, the cylinder, the plurality of spoke portions, and the plurality of cavity regions are included in a gradient index (GRIN) dielectric lens having a plurality of relative permittivities that are based on a radial distance from the center portion.

A cover device for reducing refraction of radar radio waves includes a radio wave generator configured to generate radio waves, and a cover part disposed to allow the radio waves to be incident from the radio wave generator and having an incidence section configured to be gradually increased in thicknesses in directions away from a central axis of the radio waves, thereby improving a detection accuracy through a radar by minimizing a phase difference due to refraction of a beam emitted from the radar.

A cover device for reducing refraction of radar radio waves includes a radio wave generator configured to generate radio waves, and a cover part disposed to allow the radio waves to be incident from the radio wave generator and having an incidence section configured to be gradually increased in thicknesses in directions away from a central axis of the radio waves, thereby improving a detection accuracy through a radar by minimizing a phase difference due to refraction of a beam emitted from the radar.

An apparatus includes a lens with substantially flat first surface and a substantially tiered second surface opposite the substantially flat first surface, where the substantially tiered second surface has at least a central tier and a second tier, the central tier and the second tier each having a different thickness from the other tier, and where the thickness of each tier as measured orthogonally from the substantially flat first surface is chosen to provide a delay for the signal passing through the lens to approximate the characteristics of a Luneburg type lens as a radar beam is swept across the substantially first surface.

Lensed antennas are provided that include a plurality of radiating elements and a lens positioned to receive electromagnetic radiation from at least one of the radiating elements, the lens comprising a composite dielectric material. The composite dielectric material comprises expandable gas-filled microspheres that are mixed with an inert binder, dielectric support materials such as foamed microspheres and particles of conductive material that are mixed together.

Lensed antennas are provided that include a plurality of radiating elements and a lens positioned to receive electromagnetic radiation from at least one of the radiating elements, the lens comprising a composite dielectric material. The composite dielectric material comprises expandable gas-filled microspheres that are mixed with an inert binder, dielectric support materials such as foamed microspheres and particles of conductive material that are mixed together.