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Results for “Gallium nitride”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS2017

Wideband Reconfigurable Harmonically Tuned GaN SSPA for Cognitive Radios

The paper presents the architecture of a wideband reconfigurable harmonically-tuned Gallium Nitrate (GaN) Solid State Power Amplifier (SSPA) for cognitive radios. When interfaced with the physical layer of a cognitive communication system, this amplifier topology offers broadband high efficiency through the use of multiple tuned input/output matching networks. This feature enables the cognitive radio to reconfigure the operating frequency without sacrificing efficiency. This paper additionally presents as a proof-of-concept the design, fabrication, and test results for a GaN inverse class-F type amplifier operating at X-band (8.4 GHz) that achieves a maximum output power of 5.14-W, Power Added Efficiency (PAE) of 38.6, and Drain Efficiency (DE) of 48.9 under continuous wave (CW) operation.

Cognitive↗
NASA NTRSDate not supplied

Ka-Band GaN-on-SiC MMIC Balanced High Power Amplifier for NASA's Lunar Missions

The feasibility of Ka-band GaN-on-SiC MMIC based balanced power amplifier for science data downlinks from NASA’s lunar mission assets in space is investigated. The balanced amplifier combines the RF output power from two power amplifiers using a rectangular waveguide based 3-dB hybrid coupler. The investigation includes characterizing the balanced amplifier for the overall RF output power, Gain, power added efficiency, RMS error vector magnitude for offset-QPSK, 8PSK, 16APSK, and 32APSK waveforms, 3rd order intermodulation products, and noise figure. The balanced amplifier has high output RF power and good linearity and can support high data rate downlinks from the surface and vicinity of the Moon to Earth.

Gallium Nitride↗
NASA NTRSDate not supplied

Demonstration of GaN HEMT MMIC High-Power Amplifier for Lunar Proximity Communications

In this paper, we demonstrate a Ka-band high power, high efficiency, GaN HEMT MMIC based power amplifier for communications from the lunar orbit to lunar surface. The measured results include Pout, Gain, PAE, RMS EVM for Offset-QPSK, 8PSK, 16APSK, and 32APSK waveforms, 3rd-order IMD products, noise figure, and phase noise.

Ka-band↗
NASA NTRS2024

Demonstration of GaN HEMT MMIC High-Power Amplifier for Lunar Proximity Communications

In this paper, we demonstrate a high efficiency, Ka-band (23.15 to 23.55 GHz) GaN HEMT MMIC based single-ended high power amplifier (HPA). The measured Pout, Gain, PAE, RMS EVM for Offset-QPSK, 8PSK, 16APSK, and 32APSK waveforms, 3rd-order IMD products, noise figure, and phase noise are presented. The results indicate that the saturated output power (P sat ) and the small signal Gain are on the order of 38.8 dBm (7.6 W) and 29.3 dB, respectively. The PAE at Psat is 20.0%. At the 1-dB compression point, the RMS EVM and the out-of-band spectral regrowth are less than 6% and –26 dBc respectively, for all four waveforms. Additionally, the spectrum is in compliance with the NTIA mask requirements for all four waveforms. The output 3rd-order intercept point (OIP3) is on the order of 42 dBm. The noise figure is less than 9.5 dB. The SSB phase noise spectral density is compliant with the envelope defined by the MIL-STD-188-164C. The HPA can enable proximity forward links between the orbiting Gateway/relay satellites and the lunar surface elements and cross links between relay satellites.

Ka-band↗
NASA NTRSDate not supplied

Amplifier Output Power, Gain, Efficiency, and Bandwidth: A Comparative Study of GaN HEMT MMIC Multi-Stage Power Amplifiers versus Distributed Power Amplifiers

In this paper we present first, the results of a study conducted to investigate the microwave performance of a wideband (25-31 GHz) GaN MMIC distributed high power amplifier (HPA). Second, we compare and contrast the above performance with that of an alternate architecture that relies on two HPAs to provide contiguous 25-31 GHz coverage. The two HPAs operate across 25-28 GHz and 27-31 GHz, respectively, and can be switched in and out depending on the need at any given time. The parameters investigated includes the output power, gain, power added efficiency, bandwidth, RMS error vector magnitude for offset-QPSK, 8PSK, 16APSK, and 32 APSK waveforms, 3rd-order intermodulation distortion products, noise figure, and single sideband phase noise.

MMIC↗
NASA NTRS2024

Spectrally Efficient GaN High-Power Amplifier for Lunar Communications

The paper demonstrates a spectrally efficient Ka-band GaN MMIC based high-power amplifier (HPA) that uses a waveguide 4-port magic-tee as a 2-way power combiner to combine the output from two lower power amplifier circuits. The paper presents for the prototype HPA the measured output power, gain, power added efficiency, error vector magnitude for Offset-QPSK, 8PSK, 16APSK, 32APSK, and 16QAM waveforms, waveform spectrum, and out-of-band spectral regrowth. The HPA is intended for establishing a direct communication link between assets on the lunar surface/orbit and Earth.

Gallium nitride↗
DOE OSTI2021

Thermal and Mechanical Design of a High-Voltage Power Electronics Package: Preprint

Thermal and mechanical design aspects of a power electronic package with 5-kV GaN devices are presented. Through finite element analyses, the impact of different cooling configurations and device location on the thermal performance and reliability of the package was investigated. It was found that placing the devices closer to the direct-bond-copper substrate as opposed to a centered approach in the proposed double-sided-cooling configuration resulted in improved heat dissipation. This approach also reduced the total number of attachment layers, thereby likely improving the reliability of the package. Furthermore, simulations revealed that the device location had a negligible impact on the thermomechanical behavior of the attachment layers, as they are more prone to the local coefficient of thermal expansion mismatch.

27 ARPA - Advanced Research Projects Agency-Energy↗
DOE OSTI2022

Phase I Final Report

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photocathode, gallium nitride, GaN↗