N-polar devices for ultra-high power and linearity at millimeter-wave
Abstract
N-polar Nitrogen-polar Gallium Nitride deep recess high electron mobility transistors have demonstrated record high power density with high efficiency in the W-band frequency range – over double the power density reported from other technologies. This achievement is thanks to simultaneous achievement of three factors: high breakdown voltage with dispersion well-controlled, high large signal current swing, and high gain. Nitrogen-polar devices have also demonstrated impressive linearity at 10 GHz as determined from the OIP3 to DC power ratio. These achievements will be leveraged as a starting point to significantly improve the power density, efficiency, and linearity at 30 GHz. The improvements will stem from a combination of increased device voltage swing and current swing at 30 GHz large signal conditions, as well as a method to increase the intrinsic linearity of the device. Those improvements will be based on improved epitaxy and new device processes and layout. Power cells with high absolute power will also be demonstrated. The metrics will be characterized by single-tone and two-tone load pull at the wafer level. These devices today seem to have good OIP3 to DC power ratio due to the device configuration. Further improvements to this linearity metric with simultaneous low noise figure will be achieved by a combination of reduction of the intrinsic nonlinearity, plus a novel incorporation of nonlinearity cancellation methods. These methods will be guided by experimental data and nonlinear device models, and realized by improvements to epitaxy in combination with appropriate device layout and processes. The device linearity will be characterized by two-tone load pull at the wafer level. Noise will be characterized by swept frequency noise parameters measured at the wafer level. The improvements to the device which are anticipated under this program will be beneficial for a wide range of transmitter and receiver applications.devices for ultra-high power and linearity at millimeter-wave
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 20, 2017
- Source ID
- N000141812049
Entities
People
- Umesh Mishra
Organizations
- Office of Naval Research
- United States Navy
- University of California, Santa Barbara