An alternative approach to improving the efficiency of high power radio frequency amplifiers

1992 ◽  
Vol 38 (2) ◽  
pp. 85-89 ◽  
Author(s):  
X. Lu
Keyword(s):  
Radio Frequency ◽  
High Power ◽  
Alternative Approach

scholarly journals Hardware Design of a High Dynamic Range Radio Frequency (RF) Harmonic Measurement System

Instruments ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 16 ◽  
Author(s):  
Ram Narayanan ◽  
Kyle Gallagher ◽  
Gregory Mazzaro ◽  
Anthony Martone ◽  
Kelly Sherbondy
Keyword(s):  
Radio Frequency ◽  
Measurement System ◽  
High Power ◽  
Nonlinear Distortion ◽  
Dynamic Range ◽  
Low Level ◽  
Rf Systems ◽  
Nonlinear Distortions ◽  
Circuit Elements ◽  
Rf Circuit

Radio frequency (RF) circuit elements that are traditionally considered to be linear frequently exhibit nonlinear properties that affect the intended operation of many other RF systems. Devices such as RF connectors, antennas, attenuators, resistors, and dissimilar metal junctions generate nonlinear distortion that degrades primary RF system performance. The communications industry is greatly affected by these unintended and unexpected nonlinear distortions. The high transmit power and tight channel spacing of the communication channel makes communications very susceptible to nonlinear distortion. To minimize nonlinear distortion in RF systems, specialized circuits are required to measure the low level nonlinear distortions created from traditionally linear devices, i.e., connectors, cables, antennas, etc. Measuring the low-level nonlinear distortion is a difficult problem. The measurement system requires the use of high power probe signals and the capability to measure very weak nonlinear distortions. Measuring the weak nonlinear distortion becomes increasingly difficult in the presence of higher power probe signals, as the high power probe signal generates distortion products in the measurement system. This paper describes a circuit design architecture that achieves 175 dB of dynamic range which can be used to measure low level harmonic distortion from various passive RF circuit elements.

Thermal and Mechanical Characterization of High Power GaN Packages

2011 ◽  
Vol 2011 (1) ◽  
pp. 000361-000366
Author(s):  
Don Willis ◽  
Gary Gu ◽  
Daniel Jin ◽  
Rob Dry
Keyword(s):  
Thermal Performance ◽  
High Power ◽  
Mechanical Analysis ◽  
Heat Spreader ◽  
Element Analysis ◽  
Die Attach ◽  
Viable Solution ◽  
Alternative Approach ◽  
Thermal Improvement ◽  
Multiple Devices

The typical package available for high power GaN application has the devices directly attached onto a metal flange, which could contribute significantly to the overall thermal resistance. This paper discusses an alternative approach to packaging both single and multiple devices through a heat spreader, which could potentially improve thermal performance and bring significant benefits to assembly in yields and cost. However, the heat spreader could also introduce significant CTE mis-match and potential concerns in reliability. Nonlinear 3D finite element analysis (FEA) was conducted to characterize the thermal performance and evaluate mechanical/reliability concerns. Thermal modeling considered single and multiple die applications, and the results show13–15% thermal improvement with the copper heat spreader. Mechanical analysis focused on the thermal loads of the die attach and solder reflow processes. It reveals that the die attach process is more critical as shown in the higher stress due to higher thermal load, but stress/strain levels appear to be acceptable. Thus, this alternative approach could be a viable solution.

Novel high-power radio-frequency sources for mobile ionospheric heating

2016 ◽  
Author(s):  
Brian L. Beaudoin ◽  
Jayakrishnan A. Karakkad ◽  
Charles Turner ◽  
Amith H. Narayan ◽  
Connor Thompson ◽  
...  
Keyword(s):  
Radio Frequency ◽  
High Power ◽  
Ionospheric Heating

The High-Power (3-MW) Long-Pulse (3-s) Radio-Frequency System for Ion Cyclotron Resonance Heating Experiments on TEXTOR

1987 ◽  
Vol 12 (3) ◽  
pp. 449-475 ◽  
Author(s):  
G. Van Oost ◽  
V. P. Bhatnagar ◽  
T. Delvigne ◽  
P. Descamps ◽  
F. Durodié ◽  
...  
Keyword(s):  
Radio Frequency ◽  
High Power ◽  
Cyclotron Resonance ◽  
Ion Cyclotron Resonance ◽  
Ion Cyclotron ◽  
Long Pulse

Radio-Frequency Heating of GaAs and SiC Photoconductive Switch for High-Power Applications

2006 ◽  
Vol 34 (5) ◽  
pp. 1697-1701 ◽  
Author(s):  
R. Gunda ◽  
D.S. Gleason ◽  
K. Kelkar ◽  
P. Kirawanich ◽  
W.C. Nunnally ◽  
...  
Keyword(s):  
Radio Frequency ◽  
High Power ◽  
Radio Frequency Heating ◽  
Photoconductive Switch ◽  
Frequency Heating
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