Abstract: A dual mode rotary joint as described herein can be utilized in an electromagnetic communication system such as a radar system. The dual mode rotary joint can be used to rotatably couple an antenna architecture to its mounting structure. One embodiment of the dual mode joint includes a waveguide configured to propagate radio frequency (RF) signals, and endcaps coupled to the ends of the waveguide. Each endcap is reflective for RF signals and transmissive for optical signals.

Abstract: A dual mode rotary joint as described herein can be utilized in an electromagnetic communication system such as a radar system. The dual mode rotary joint can be used to rotatably couple an antenna architecture to its mounting structure. One embodiment of the dual mode joint includes a waveguide configured to propagate radio frequency (RF) signals, and endcaps coupled to the ends of the waveguide. Each endcap is reflective for RF signals and transmissive for optical signals.

Abstract: Providing multi-spot inverse synthetic aperture radar (ISAR) imagery is disclosed. Embodiments of techniques in accordance with the present disclosure may advantageously improve multiple target discrimination, detection, identification, and tracking using ISAR imaging. In an embodiment, an inverse synthetic aperture radar (ISAR) method for producing multiple ISAR images from a single waveform includes transmitting a chirp signal into a dwell surveyed by the antenna beamwidth. Multiple dechirp reference signals may be generated to demodulate return signals from the dwell at multiple selected intervals within a pulse repetition interval (PRI) to create demodulated signals.

Abstract: Providing multi-spot inverse synthetic aperture radar (ISAR) imagery is disclosed. Embodiments of techniques in accordance with the present disclosure may advantageously improve multiple target discrimination, detection, identification, and tracking using ISAR imaging. In an embodiment, an inverse synthetic aperture radar (ISAR) method for producing multiple ISAR images from a single waveform includes transmitting a chirp signal into a dwell surveyed by the antenna beamwidth. Multiple dechirp reference signals may be generated to demodulate return signals from the dwell at multiple selected intervals within a pulse repetition interval (PRI) to create demodulated signals.

Abstract: An antenna system for communicating electromagnetic and optical signals using a common aperture is provided. The system includes at least one optical phased array terminal integrated with an optically transparent electromagnetic antenna such that the optically transparent electromagnetic antenna and the optical phased array terminal share a common aperture. The optically transparent electromagnetic antenna includes a substrate fabricated of a substantially electrically non-conductive material that is substantially optically transparent to optical signals having a wavelength within a specific portion of the optical spectrum. An antenna element layer, including an array of electromagnetic antenna elements electrically connected by transmission lines and a plurality of phase shifters electrically connected to the electromagnetic antenna elements is disposed onto the substrate.