Figure 1 depicts a monolithic microwave integrated-circuit (MMIC) single-stage amplifier containing an InP-based high- electron-mobility transistor (HEMT) plus coplanar-waveguide (CPW) transmission lines for impedance matching and input and output coupling, all in a highly miniaturized layout as needed for high performance at operating frequencies of hundreds of gigahertz. This is one in a series of devices that are intermediate products of a continuing effort to develop advanced MMIC amplifiers for sub-millimeter-wavelength imaging systems, scientific instrumentation, heterodyne receivers, and other applications.
The amplifier is designed for operation at a nominal frequency of 340 GHz. The HEMT in this amplifier has a gate length of 35 nm and two fingers each 15 μm wide. The CPWs have a ground- to-ground spacing of only 14 μm. The inclusion of quarter-wavelength-long CPWs for impedance matching and of on-chip shunt capacitors makes it possible to obtain about 5 dB of gain with respectable values of input and output return losses at the design frequency of 340 GHz (see Figure 2). This is among the highest gains per stage at this frequency reported to at the time of this work. Moreover, the measurement data suggest potential for further increase in gain with frequency beyond the 345-GHz limit of the test equipment used to perform the measurements.
This work was done by David Pukala, Lorene Samoska, King Man Fung, and Todd Gaier of Caltech and W. R. Deal, Gerry Mei, Vesna Radisic, and Richard Lai of Northrop Grumman Corporation for NASA's Jet Propulsion Laboratory. The contributors would like to acknowledge the support of Dr. Mark Rosker and the Army Research Laboratory. This work was supported by the DARPA SWIFT Program and Army Research Laboratory under the DARPA MIPR no.06-U037 and ARL Contract no. W911QX-06-C-0050.
NPO-44962
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Compact, Single-Stage MMIC InP HEMT Amplifier
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Overview
The document outlines the advancements in testing capabilities for Monolithic Millimeter-wave Integrated Circuits (MMIC) and Submillimeter-wave Integrated Circuits (S-MMIC) at NASA's Jet Propulsion Laboratory (JPL). The focus is on the development of on-wafer and waveguide testing methods for various MMIC components, including amplifiers, oscillators, transistors, and diode circuits, with capabilities extending up to 500 GHz.
The authors, including L. Samoska and A. K. Fung, detail the state-of-the-art techniques for conducting S-parameter measurements, noise figure assessments, and power measurements on-wafer, specifically up to 350 GHz. They reference the first S-MMIC chips tested at JPL, which were fabricated at Northrop Grumman Corporation and included single-stage High Electron Mobility Transistor (HEMT) amplifiers that achieved a gain of 2.5 dB at 300 GHz.
The document also discusses the evolution of HEMT doubler technology, which previously faced challenges due to measurement uncertainties when tested outside recommended frequency ranges. Recent collaborations with GGB Industries and OML Laboratories have led to the development of submillimeter-wave test sets that can measure noise figures and power data with an accuracy of less than ±1 dB up to 270 GHz.
Key components required for these measurements are described, along with recent test results on MMIC and S-MMIC chips. The authors express plans for future wafer probing capabilities that will extend testing up to 500 GHz, indicating ongoing advancements in this field.
The document serves as a technical support package under NASA's Commercial Technology Program, aimed at disseminating aerospace-related developments with broader technological, scientific, or commercial applications. It emphasizes the importance of compliance with U.S. export regulations and the proprietary nature of some information contained within.
For further inquiries or assistance, the document provides contact information for the Innovative Technology Assets Management at JPL, encouraging collaboration and exploration of the research and technology in this area. Overall, the document highlights significant progress in MMIC and S-MMIC testing, showcasing JPL's commitment to advancing aerospace technology.
