An Upgraded KID Camera for Long-Range Imaging Through Optical Obscurants
Abstract
The ONR aims to develop mm-wave imaging technology to enable long-range target detection through optical obscurants such as fog and clouds. These wavelengths are particularly attractive due to the relatively low opacity of the obscurants paired with better diffraction-limited angular resolution than traditional radio techniques at longer wavelengths. With support from the ONR, we have nearly completed the development of a 3,840 detector 140 GHz imager with a 1.5 m telescope.We propose the following six efforts to further advance this technology for the ONR. We will complete the existing imager and perform a dockside demonstration of its performance at the Naval base in Point Loma. We will fully weatherize the telescope for long-term operation in a marine environment. We will provide an initial demonstration of a distributed aperture system based on low-loss flexible dielectric waveguides and a Si lens using a set of 5 apertures coupled via 4 m long commercially-available waveguides. We will also demonstrate the ability to fabricate custom waveguides to allow for more general configurations in the future. If successful, we expect that a distributed aperture system could be scaled to hundreds of apertures with waveguides10{15 m in length. Such a system would provide an order of magnitude improvement in angular resolution while also allowing for electronic beam steering. We will add a cryogenic aperture stop to the optical design. This will provide improve angular resolution and also better noise performance via a reduction in optical loading. We will upgrade the KID detector arrays to provide simultaneous dual-polarization dual band 94 and 140 GHz imaging, thus increasing the detector count by a factor of two and providing maximum sensitivity and versatility for different weather conditions with the dual band operation. This KID design will also eliminate the challenging tile-thinning operation required for fabrication of the current detectors, along with the waveguide/horn block plate thought to be responsible for microphonic pickup noise. We therefore expect more reliable and robust fabrication and better noise performance. In addition, this new KID design would allow for potential future upgrades to provide simultaneous imaging in four or more bands. We will upgrade the readout electronics to make use of new RF System on a Chip (RFSoC) technology. This will significantly reduce the SWaP of the readout system, and is further motivated by the recent end-of-life announcement by Digicom Electronics for our existing readout system that is based on the CASPER ROACH boards.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 08, 2020
- Source ID
- N000142012430
Entities
People
- Jack Sayers
Organizations
- California Institute of Technology
- Office of Naval Research
- United States Navy