Modules containing multiple monolithic microwave integrated-circuit (MMIC) chips have been built as prototypes of transmitting/receiving (T/R) modules for millimeter-wavelength radar systems, including phased-array radar systems to be used for diverse purposes that could include guidance and avoidance of hazards for landing spacecraft, imaging systems for detecting hidden weapons, and hazard-avoidance systems for automobiles. Whereas prior landing radar systems have operated at frequencies around 35 GHz, the integrated circuits in this module operate in a frequency band centered at about 150 GHz. The higher frequency (and, hence, shorter wavelength), is expected to make it possible to obtain finer spatial resolution while also using smaller antennas and thereby reducing the sizes and masses of the affected systems.

The Module Housing Contains Cavities wherein MMIC chips are placed.
The integrated circuits contained in the present T/R modules include low-noise amplifiers and power amplifiers previously reported in NASA Tech Briefs, variously, as separate chips or modules in “MMIC HEMT Power Amplifier for 140 to 170 GHz” (NPO-30127), Vol. 27, No. 11 (November 2003), page 49; and “Power-Amplifier Module for 145 to 165 GHz” (NPO-40260), Vol. 31, No. 2 (February 2007), page 38. The module housings (see figure) were made from gold-plated brass and include flanges for input and output WR-5 waveguides. [A WR-5 waveguide, nominally designed for operation in the G Band (140 to 220 GHz), has an internal cross section of 0.0510 by 0.0255 in. (about 1.30 by 0.65 mm).]

Each module contains two branches: one for transmitting and one for receiving. Two modules — one containing only the transmitting circuitry, the other containing only the receiving circuitry — were fabricated for initial experiments in which they were tested separately. The transmitting-only module contained two MMIC power-amplifier chips that were fabricated at HRL Laboratories, LLC. The chips were separated by microstrip transmission lines made partly of alumina, and a WR-5 electric-field-plane probe was used to make the transition from the microstrip mode to the waveguide mode. Wire bonds were used to connect the transmission lines to the chips. DC connections were made by means of feedthroughs mounted through the module and connected to bias circuit boards with external multi-pin connectors. At the time of reporting the information for this article, the transmitting-only module had been tested and found to afford about 14 dB of gain over the frequency range from 148 to 150 GHz.

This work was done by Lorene A. Samoska, David M. Pukala, Mary M. Soria, and Gregory A. Sadowy of Caltech for NASA’s Jet Propulsion Laboratory. NPO-46074

Topics:
Amplifiers Antennas Connectors and terminals Downsizing Electric power grid Electrical systems Electronic equipment Imaging and visualization Integrated circuits Optics Radar Semiconductors & ICs Waveguides
This Brief includes a Technical Support Package (TSP).
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T/R Multi-Chip MMIC Modules for 150 GHz

(reference NPO-46074) is currently available for download from the TSP library.

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NASA Tech Briefs Magazine

This article first appeared in the June, 2009 issue of NASA Tech Briefs Magazine (Vol. 33 No. 6).

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Overview

The document is a Technical Support Package from NASA's Jet Propulsion Laboratory (JPL) concerning T/R Multi-Chip MMIC (Monolithic Microwave Integrated Circuit) Modules designed for operation at 150 GHz. It is part of NASA Tech Briefs, specifically referenced as NPO-46074, and aims to disseminate information about aerospace-related technological advancements that may have broader scientific, commercial, or technological applications.

The document includes various sketches and diagrams that illustrate the design and functionality of the T/R modules. Key features highlighted include the RF cavity in transmit mode, which shows the configuration of input and output waveguides, E-plane transitions, microstrip lines, and power amplifier MMICs. These components are crucial for the effective transmission and reception of microwave signals, which are essential in radar and communication systems.

One of the notable illustrations is a close-up view of the RF cavity in transmit mode, detailing the arrangement of microstrip lines and the power amplifier MMIC, along with bypass capacitors positioned above and below the chip. This design is indicative of the advanced engineering involved in ensuring optimal performance and reliability in high-frequency applications.

The document also provides a top view of the T/R module, showcasing both transmit and receive chip cavities, along with the associated input and output waveguides. This comprehensive view aids in understanding the spatial arrangement and integration of the various components within the module.

Additionally, the Technical Support Package emphasizes compliance with U.S. export regulations and the proprietary nature of the information contained within. It encourages users to adhere to applicable regulations when utilizing the information provided.

For further inquiries or assistance regarding research and technology in this area, the document lists contact information for the Innovative Technology Assets Management office at JPL.

In summary, this Technical Support Package serves as a resource for understanding the design and application of T/R Multi-Chip MMIC Modules for 150 GHz, showcasing JPL's commitment to advancing aerospace technology and facilitating innovative partnerships.