Method of optimizing a ga-nitride device material structure for a frequency multiplication device

Abstract

A preferred method of optimizing a Ga-nitride device material structure for a frequency multiplication device comprises:determining the amplitude and frequency of the input signal being multiplied in frequency;providing a Ga-nitride region on a substrate;determining the Al percentage composition and impurity doping in an AlGaN region positioned on the Ga-nitride region based upon the power level and waveform of the input signal and the desired frequency range in order to optimize power input / output efficiency; andselecting an orientation of N-face polar GaN or Ga-face polar GaN material relative to the AlGaN / GaN interface so as to orient the face of the GaN so as to optimize charge at the AlGaN / GaN interface. A preferred embodiment comprises an anti-serial Schottky varactor comprising: two Schottky diodes in anti-serial connection; each comprising at least one GaN layer designed based upon doping and thickness to improve the conversion efficiency.

Description

GOVERNMENT INTEREST[0001]The embodiments herein may be manufactured, used, and / or licensed by or for the United States Government without the payment of royalties thereon.BACKGROUND OF THE INVENTION[0002]A frequency multiplier (e.g. a tripler) is a device that takes an input signal at 30 GHz and converts some of the energy from this input signal into an output signal at 90 GHz. Because a frequency multiplier is used to generate an output at a different frequency from the input, one of the goals of an optimized structure is efficient operation whereby the energy transferred to the new frequency at the output is maximized. The same methodology for the device / structure and optimization can also be applied to obtain higher harmonics, such as the fifth order of conversion, which will be useful for sub-millimeter wave signal generation.[0003]Varactor multipliers have first been conceptualized back in the mid 1960s. However, little has been done insofar as a conceptual method on how to opt...

AI Technical Summary

Benefits of technology

[0014]Optionally one can make a tradeoff by determining if the efficiency gain from increasing the aluminum percent is a better outcome vs. as it may also lead to reduced lifetime due to heating of the device, but if the cost savings from increased efficiency is worth the reduced lifetime, this is a good result.

[0027]Optionally the preferred embodiment comprises two Schottky diodes that are inhomogeneously doped and are in anti-serial connection, each Schottky diode further comprising at least one semi-insulating wide bandgap AlGaN layer which is designed based on choice of composition, doping, and thickness to greatly improve the conversion efficiency.

Problems solved by technology

However, little has been done insofar as a conceptual method on how to optimize the device-material structure for highest frequency conversion efficiency at a particular output power level.

Power absorbed in the varactor also increases as aluminum percent increases, affecting reliability and power transfer.

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