Abstract: An antenna includes a waveguide defined by a gap between a backplane with radial support ribs and a facesheet, a teardrop-shaped feed pin at a center of the backplane, and a foam spacer between the backplane and facesheet. An outward facing side of the facesheet includes thermal paint. The facesheet includes pairs of through-hole slots for releasing portions of a wave of radiation in the waveguide to generate a transmit-beam or to receive the receive-beam to generate the wave of radiation. The pairs may be disposed as a spiral array about a center of the facesheet. Each of the pairs may include first and second slots. A length of the second slot is oriented approximately perpendicular to a length of the first slot. Dispositions of the slots are set by a computer process. The dispositions optimize a trade-off between transmit and receive gains.

Abstract: An antenna includes a waveguide defined by a gap between a backplane with radial support ribs and a facesheet, a teardrop-shaped feed pin at a center of the backplane, and a foam spacer between the backplane and facesheet. An outward facing side of the facesheet includes thermal paint. The facesheet includes pairs of through-hole slots for releasing portions of a wave of radiation in the waveguide to generate a transmit-beam or to receive the receive-beam to generate the wave of radiation. The pairs may be disposed as a spiral array about a center of the facesheet. Each of the pairs may include first and second slots. A length of the second slot is oriented approximately perpendicular to a length of the first slot. Dispositions of the slots are set by a computer process. The dispositions optimize a trade-off between transmit and receive gains.

Abstract: An antenna includes a waveguide defined by a gap between a backplane with radial support ribs and a facesheet, a teardrop-shaped feed pin at a center of the backplane, and a foam spacer between the backplane and facesheet. An outward facing side of the facesheet includes thermal paint. The facesheet includes pairs of through-hole slots for releasing portions of a wave of radiation in the waveguide to generate a transmit-beam or to receive the receive-beam to generate the wave of radiation. The pairs may be disposed as a spiral array about a center of the facesheet. Each of the pairs may include first and second slots. A length of the second slot is oriented approximately perpendicular to a length of the first slot. Dispositions of the slots are set by a computer process. The dispositions optimize a trade-off between transmit and receive gains.

Abstract: A method including receiving a monopulse transmission by a monopulse antenna determining an angle of arrival of the monopulse transmission, using processing circuitry operably coupled to the monopulse antenna, determining, using the processing circuitry, an angle error for a high gain antenna based on the angle of arrival of the monopulse transmission, and causing the positioning of the high gain antenna based on the angle error.

Abstract: A method including receiving a monopulse transmission by a monopulse antenna determining an angle of arrival of the monopulse transmission, using processing circuitry operably coupled to the monopulse antenna, determining, using the processing circuitry, an angle error for a high gain antenna based on the angle of arrival of the monopulse transmission, and causing the positioning of the high gain antenna based on the angle error.

Abstract: A passive element is provided to facilitate passive detection of analytes, such as analytes, using an electromagnetic probe beam. The probe beam may be provided by a radar and/or lidar system. In one example, a passive element comprises a reference dipole and a detection dipole, the detection dipole having an associated analyte-sensitive element, such as a chemoresistive or bioresistive element. When the analyte-sensitive element is in a modified conducting state due to the presence of an analyte, the detection cross section is modified whereas a reference cross section is substantially unchanged by the presence of the analyte. A passive element may comprise a frequency selective surface, for example including a frequency-selective surface (FSS) embedded in a dielectric layer and using an analyte-sensitive impedance layer to modify the electromagnetic absorption properties, allowing analyte detection.