Integrated Lens Antennas for Multi-Pixel Receivers
- Monday, 24 October 2011
This integrated lens antenna could enable high-resolution, three-dimensional imaging radar for homeland security applications.
Future astrophysics and planetary
experiments are expected to require
large focal plane arrays with thousands
of detectors. Feedhorns have excellent
performance, but their mass, size, fabrication
challenges, and expense become
prohibitive for very large focal plane
arrays. Most planar antenna designs produce
broad beam patterns, and therefore
require additional elements for efficient
coupling to the telescope optics,
such as substrate lenses or micromachined
Dielectric Silicon Micro Lens (left) is shown with a possible array concept (right)." class="caption" align="right">An antenna array with integrated silicon
microlenses that can be fabricated
photolithographically effectively addresses
these issues. This approach eliminates
manual assembly of arrays of lenses and
reduces assembly errors and tolerances.
Moreover, an antenna array without
metallic horns will reduce mass of any
planetary instrument significantly.
The design has a monolithic array of
lens-coupled, leaky-wave antennas operating
in the millimeter- and submillimeter-wave frequencies. Electromagnetic
simulations show that the electromagnetic
fields in such lens-coupled antennas
are mostly confined in approximately
12–15°. This means that one needs to design a small-angle sector lens that is
much easier to fabricate using standard
lithographic techniques, instead of a full
hyper-hemispherical lens. Moreover, this
small-angle sector lens can be easily integrated
with the antennas in an array for
multi-pixel imager and receiver implementation.
The leaky antenna is
designed using double-slot irises and fed
with TE10 waveguide mode. The lens
implementation starts with a silicon substrate.
Photoresist with appropriate
thickness (optimized for the lens size) is
spun on the substrate and then reflowed
to get the desired lens structure.
An antenna array integrated with individual lenses for higher directivity and excellent beam profile will go a long way in realizing multi-pixel arrays and imagers. This technology will enable a new generation of compact, low-mass, and highly efficient antenna arrays for use in multi-pixel receivers and imagers for future planetary and astronomical instruments. These antenna arrays can also be used in radars and imagers for contraband detection at stand-off distances.
This will be enabling technology for future balloon-borne, smaller explorer class mission (SMEX), and other missions, and for a wide range of proposed planetary sounders and radars for planetary bodies.
This work was done by Choonsup Lee and
Goutam Chattopadhyay of Caltech and
Nuria Llombart Juan for NASA’s Jet
Propulsion Laboratory. For more information,
In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:
• Innovative Technology Assets Management JPL
• Mail Stop 202-233
• 4800 Oak Grove Drive
• Pasadena, CA 91109-8099