A radome-reflector assembly includes a generally domed reflector having a peripheral rim and a radome assembly. The radome assembly includes: an annular ring having a front wall and a side wall: a disk that fits within the ring: and an RF-compliant absorber, wherein the rim of the reflector fits within the side wall. The radome assembly further comprises a clip that engages the rim and the ring to secure the reflector to the radome assembly.

A printed circuit board (PCB) module may include a PCB with at least one internal PCB element and at least one external PCB element, a shielding layer fabricated from a tunable metamaterial absorber, and a structure housing the PCB. The at least one internal PCB element may be embedded between adjacent layers of the PCB. The at least one external PCB element may be coupled to an exterior surface of the PCB. The shielding layer may be tuned in response to the at least one measurement of the EMI emission and a determination of a frequency of the EMI emission from the at least one measurement. The tuning of the shielding layer may include adjusting a plurality of fins within a plurality of elements of the metamaterial absorber to absorb at least a portion of the EMI emission.

A printed circuit board (PCB) module may include a PCB with at least one internal PCB element and at least one external PCB element, a shielding layer fabricated from a tunable metamaterial absorber, and a structure housing the PCB. The at least one internal PCB element may be embedded between adjacent layers of the PCB. The at least one external PCB element may be coupled to an exterior surface of the PCB. The shielding layer may be tuned in response to the at least one measurement of the EMI emission and a determination of a frequency of the EMI emission from the at least one measurement. The tuning of the shielding layer may include adjusting a plurality of fins within a plurality of elements of the metamaterial absorber to absorb at least a portion of the EMI emission.

An antenna arrangement suitable for a vehicle radar transceiver. The antenna arrangement includes a radiating layer having a surface, the surface delimited by a surface boundary. One or more apertures are arranged on the surface. The antenna arrangement further includes one or more surface current suppressing members arranged on the surface. The one or more surface current suppressing members are arranged to suppress a surface current from an aperture to the surface boundary. The one or more surface current suppressing members include one or more grooves.

Disclosed herein is a noise suppression sheet that includes a magnetic sheet and a first metal layer provided on one surface of the magnetic sheet. The first metal layer has a plurality of annular slits. The first metal layer is divided into a plurality of first areas surrounded respectively by the plurality of slits and a second area surrounding an entire periphery of each of the plurality of slits.

A transparent stealth structure includes: a first transparent film structure stacked on a front surface of a transparent base, the first transparent film structure causing energy loss of incident electromagnetic waves having a target frequency to change a phase of transmitted electromagnetic waves propagating toward the transparent base; and a second transparent film structure stacked on a back surface of a transparent base, the second transparent film structure reflecting the transmitted electromagnetic waves having passed through the transparent base while adjusting a phase of reflected waves propagating toward the first transparent film structure, wherein the first transparent film structure includes a first front transparent conductive pattern having a first sheet resistance and a second front transparent conductive pattern filling a region, and the second transparent film structure includes a first rear transparent conductive pattern having a third sheet resistance and a second rear transparent conductive pattern filling a region.

An omnidirectional vertically polarized antenna. A number of antenna elements are each fabricated on a backing, such as a printed circuit board. The front of each antenna element has conductive strips and slots, arranged in an alternating pattern. The back of each antenna element has an antenna feed circuit. An electrically absorptive layer is attached to the back of each antenna element. The antenna elements are assembled together in a nonconductive housing with circumferentially arranged compartments that receive the antenna elements.

A stealth antenna includes an electromagnetic wave absorbing structure and an antenna patch embedded in the electromagnetic wave absorbing structure. The electromagnetic wave absorbing structure includes an upper dielectric layer, a lower dielectric layer and a spacer disposed between the upper dielectric layer and the lower dielectric layer. The upper dielectric layer includes a dielectric fabric and a conductive coating layer combined with at least a portion of the dielectric fabric. The lower dielectric layer includes a dielectric fabric and has a dielectric constant lower than that of the upper dielectric layer. The antenna patch is disposed between the spacer and the lower dielectric layer.

A stealth antenna includes an electromagnetic wave absorbing structure and an antenna patch embedded in the electromagnetic wave absorbing structure. The electromagnetic wave absorbing structure includes an upper dielectric layer, a lower dielectric layer and a spacer disposed between the upper dielectric layer and the lower dielectric layer. The upper dielectric layer includes a dielectric fabric and a conductive coating layer combined with at least a portion of the dielectric fabric. The lower dielectric layer includes a dielectric fabric and has a dielectric constant lower than that of the upper dielectric layer. The antenna patch is disposed between the spacer and the lower dielectric layer.

A radio frequency (RF) aperture includes an array of electrically conductive tapered projections arranged to define a curved aperture surface, such as a semi-cylinder aperture surface, or a cylinder aperture surface (which may be constructed as two semi-circular aperture surfaces mutually arranged to define the cylinder aperture surface). The RF aperture may further include a top array of electrically conductive tapered projections arranged to define a top aperture surface. The top aperture surface may be planar, and a cylinder axis of cylinder aperture surface may be perpendicular to the plane of the planar top aperture surface. The RF aperture may further include baluns mounted on at least one printed circuit board, each having a balanced port electrically connected with two neighboring electrically conductive tapered projections of the array and further having an unbalanced port.