A 155W −95.6 dB THD+N GaN-based Class-D Audio Amplifier With LC Filter Nonlinearity Compensation

Silicon MOSFETs-based medium-power (< 50W) Class-D amplifiers (CDAs) switching in the MHz range have gained popularity in recent years, which achieves better linearity thanks to a higher loop gain in the audio band while enabling the use of LC filters with higher cut-off frequencies. However, for high-power (>100 W) CDAs, such switching...

High-Power Digital Transmitters for Wireless Infrastructure Applications (A Feasibility Study)

Fully digital transmitters (DTXs) have the potential of replacing analog-intensive transmitter (TX) line-ups in future massive multiple-input and multiple-output (mMIMO) systems since they hold the promise of higher system integration level and energy efficiency. DTX operation so far has been limited to low RF output powers. This article...

Research on Thermal-Mechanical Properties of GaN Power Module Based on QFN Package by Using Nano Copper/Silver Sinter Paste

The wide-bandgap semiconductors represented by GaN have a broad application prospect because of their high service temperature and high switch frequency. Quad-Flat-No-Lead (QFN) Package is currently one of the mainstream packaging methods due to its low cost and high efficiency. However, the low reliability of QFN used in GaN devices is still...

Low Leakage and High Forward Current Density Quasi-Vertical GaN Schottky Barrier Diode With Post-Mesa Nitridation

In this brief, a high-performance quasi-vertical GaN Schottky barrier diode (SBD) on sapphire substrate with post-mesa nitridation process is reported, featuring a low damaged sidewall with extremely low leakage current. The fabricated SBD with a drift layer of 1 μm has achieved a very high ON/OFF current ratio (Iscriptscriptstyle ON...

High-power and broadband microwave detection with a quasi-vertical GaN Schottky barrier diode by novel post-mesa nitridation

We report a high-performance GaN Schottky barrier diode (SBD) on a sapphire substrate with a novel post-mesa nitridation technique and its application in a high-power microwave detection circuit. The fabricated SBD achieved a very high forward current density of 9.19 kA cm-2 at 3 V, a low specific on-resistance (RON,sp) of 0.22 mO cm2 and...

Optimization of mesa etch for a quasi-vertical gan schottky barrier diode (Sbd) by inductively coupled plasma (icp) and device characteristics

The optimization of mesa etch for a quasi-vertical gallium nitride (GaN) Schottky barrier diode (SBD) by inductively coupled plasma (ICP) etching was comprehensively investigated in this work, including selection of the etching mask, ICP power, radio frequency (RF) power, ratio of mixed gas, flow rate, and chamber pressure, etc. In particular...

Suspended AlGaN/GaN HEMT NO₂ Gas Sensor Integrated with Micro-heater

We developed an AlGaN/GaN high electron mobility transistor (HEMT) sensor with a tungsten trioxide (WO₃) nano-film modified gate for nitrogen dioxide (NO₂) detection. The device has a suspended circular membrane structure and an integrated micro-heater. The thermal characteristic of the Platinum (Pt) micro-heater and the...

Suppression of persistent photoconductivity AlGaN/GaN heterostructure photodetectors using pulsed heating

This paper demonstrates a method to reduce the decay time in AlGaN/GaN photodetectors by a pulsed heating mode. A suspended AlGaN/GaN heterostructure photodetector integrated with a micro-heater is fabricated and characterized under ultraviolet illumination. We have observed that the course of persistent photoconductivity was effectively...

Review of the recent progress on GaN-based vertical power Schottky barrier diodes (SBDs)

Gallium nitride (GaN)-based vertical power Schottky barrier diode (SBD) has demonstrated outstanding features in high-frequency and high-power applications. This paper reviews recent progress on GaN-based vertical power SBDs, including the following sections. First, the benchmark for GaN vertical SBDs with different substrates (Si, sapphire, and...

Mechanical, thermodynamic and electronic properties of wurtzite and zinc-blende GaN crystals

For the limitation of experimental methods in crystal characterization, in this study, the mechanical, thermodynamic and electronic properties of wurtzite and zinc-blende GaN crystals were investigated by first-principles calculations based on density functional theory. Firstly, bulk moduli, shear moduli, elastic moduli and Poisson's ratios...

Pt-AlGaN/GaN HEMT-sensor layout optimization for enhancement of hydrogen detection

This paper reports on the layout optimization of Pt-AlGaN/GaN HEMT-sensors for enhancing hydrogen sensor performance. Sensors with gate width and length ratios W_g/L_g from 0.25 to 10 were designed, fabricated and tested for the detection of hydrogen gas at 200 °C. Sensitivity, sensing current variation and transient...

Single Photon Counting UV Solar-Blind Detectors Using Silicon and III-Nitride Materials

Ultraviolet (UV) studies in astronomy, cosmology, planetary studies, biological and medical applications often require precision detection of faint objects and in many cases require photon-counting detection. We present an overview of two approaches for achieving photon counting in the UV. The first approach involves UV enhancement of photon...

Energy Efficient and Compact RF High-Power Amplifiers

The main objectives of this thesis are to improve the energy efficiency and physical form-factor of high-power amplifiers in base station applications. As such, the focus of this dissertation is placed on the outphasing amplifier concept, which can offer high-efficiency, good linearity and excellent opportunities for system integration. With...

Lanthanide impurity level location in GaN, AlN, and ZnO

A method that has proven succesful in locating the energy levels of divalent and trivalent lanthanide ions (Ce, Pr,..., Eu,...Yb, Lu) in wide band gap inorganic compounds like YPO4 and CaF2 is applied to locate lanthanide levels in the wideband semiconductors GaN, AlN, their solid solutions AlxGa1-xN, and ZnO. The proposed schemes provide a...