High-performance mixers at terahertz frequencies require good matching between the coupling circuits such as antennas and local oscillators and the diode embedding impedance. With the availability of amplifiers at submillimeter wavelengths and the need to have multi-pixel imagers and cameras, planar mixer architecture is required to have an integrated system. An integrated mixer with planar antenna provides a compact and optimized design at terahertz frequencies. Moreover, it leads to a planar architecture that enables efficient interconnect with submillimeter-wave amplifiers.
In this architecture, a planar slot antenna is designed on a thin gallium arsenide (GaAs) membrane in such a way that the beam on either side of the membrane is symmetric and has good beam profile with high coupling efficiency. A coplanar waveguide (CPW) coupled Schottky diode mixer is designed and integrated with the antenna. In this architecture, the local oscillator (LO) is coupled through one side of the antenna and the RF from the other side, without requiring any beamsplit-
ters or diplexers. The intermediate frequency (IF) comes out on a 50-ohm CPW line at the edge of the mixer chip, which can be wire-bonded to external circuits. This unique terahertz mixer has an integrated single planar antenna for coupling both the radio frequency (RF) input and LO injection without any diplexer or beamsplitters. The design utilizes novel planar slot antenna architecture on a 3-μm-thick GaAs membrane.
This work is required to enable future multi-pixel terahertz receivers for astrophysics missions, and lightweight and compact receivers for planetary missions to the outer planets in our solar system. Also, this technology can be used in terahertz radar imaging applications as well as for testing of quantum cascade lasers (QCLs).
This work was done by Goutam Chattopadhyay, Imran Mehdi, John J. Gill, Choonsup Lee, and Nuria Llombart of Caltech for NASA’s Jet Propulsion Laboratory and Bertrand Thomas of Oak Ridge Associated Universities. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp under the Physical Sciences category. NPO-46880
This Brief includes a Technical Support Package (TSP).
Planar Submillimeter-Wave Mixer Technology With Integrated Antenna
(reference NPO-46880) is currently available for download from the TSP library.
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Overview
The document discusses NASA's Technical Support Package for the Planar Submillimeter-Wave Mixer Technology with Integrated Antenna, identified as NPO-46880. This technology addresses the challenges of achieving high-performance mixers at terahertz frequencies, which require effective matching between coupling circuits, such as antennas and local oscillators, and the diode embedding impedance.
The proposed solution is an integrated mixer that features a planar antenna, resulting in a compact and optimized design suitable for terahertz applications. This architecture allows for efficient interconnection with submillimeter-wave amplifiers, which are crucial for enhancing signal processing capabilities at these high frequencies.
A key aspect of the design is the planar slot antenna, which is fabricated on a thin Gallium Arsenide (GaAs) membrane. This design ensures that the radiation beam is symmetric on both sides of the membrane, providing a high-quality beam profile and excellent coupling efficiency. The architecture incorporates a coplanar waveguide (CPW) coupled Schottky diode mixer that is seamlessly integrated with the antenna. Notably, the local oscillator (LO) signal is coupled from one side of the antenna while the radio frequency (RF) signal is received from the opposite side, eliminating the need for additional components like beam splitters or diplexers.
The intermediate frequency (IF) output is delivered through a 50 Ohm CPW line located at the edge of the mixer chip, facilitating easy wire-bonding to external circuits. This innovative design not only simplifies the overall architecture but also enhances the performance of the terahertz receiver chip.
The document emphasizes the novelty of this approach, highlighting the unique integration of the planar slot antenna with the mixer, which results in a compact and high-performance device. The technology is positioned within the broader context of aerospace-related developments, suggesting potential applications beyond its initial scope.
Overall, the Technical Support Package serves as a resource for understanding the advancements in planar submillimeter-wave mixer technology and its implications for future aerospace and commercial applications. It also provides contact information for further inquiries related to research and technology in this field, underscoring NASA's commitment to sharing innovative developments with wider technological and scientific communities.
