Empowering GaN HEMT models: The gateway for power amplifier design

In this paper, an accurate parasitic parameters extraction method based on full wave electromagnetic for 0.1 μm GaN high electron mobility transistors (HEMTs) smallsignal equivalent circuit up to 110 GHz is presented. To describe the distribution effects of HEMTs electrodes at extremely high frequency, a 2-stage distributed transmission line equivalent circuit model is also presented. To minimize the distribution effects, a shorter gate-width device, called partial transistor model, is used to extract the second stage (N = 2) parasitic capacitance before extracting the first stage (N = 1) parameters. An AlGaN/GaN HEMT with gate length of 0.1 μm is used for validation, and the experimental results show that good agreement has been achieved between measured and simulated scattering (S) parameters up to 110 GHz. KEYWORDSAlGaN/GaN HEMTs, high frequency distribution effects, parasitic parameter model | INTRODUCTIONGaN-based high electron mobility transistors (HEMTs) are one of the most attractive solid device for high-power and high-frequency microwave devices. 1 Accurate models 2-4 can promote the efficiency of circuit design and is essential to circuit designer. With the increasing operation frequency of GaN HEMT, characterization of GaN HEMTs up to W-band is highly attracted recently. [5][6][7] At extremely high frequency, much more parasitic parameters for transistor need to be considered to account for high-frequency effects. However, the complicated parasitic parameters network will dramatically increase the difficulty of parameters extraction. Most of the papers have to use optimization method, which have challenges like multivalues problem, nonphysical results, and difficult to separate the parasitic capacitance and intrinsic capacitance. 8 It is need the guessed starting values of the parasitic parameters and a family of scaling devices be available for measurement to get the optimal values for device by Sergio. 9 Zlatica 10 used artificial neural networks for constructing a temperature-dependent model representing the small-signal scattering (S-) parameters of a GaN HEMT over a wide bias range and a board frequency range, while this method need tremendous measured data and high computer configuration. In Jarndal and Kompa, 11 a new parasitic elements extraction method based on cold pinch-off conditions was developed. This method uses only a cold-parameter measurement for accurate determination of the parasitic elements. The main advantage of this method is that it gives reliable values for the parasitic elements of the device without need for additional measurements or separate test pattern. But it needs hard task, when there are much more parasitic parameters up 110 GHz. Giovanni 12 used a new and simple T-network composed by lumped elements for representing the investigated GaN HEMT under a forward "cold" condition, which takes into account the capacitive effects of S11 and S22. All extrinsic parasitic elements are evaluated under "cold-FET" conditions without forward biasing the gate terminal. 13...

Section: Parasitic Parameter Extraction Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An accurate parasitic parameters extraction method based on FW‐EM for AlGaN/GaN HEMT up to 110 GHz

Jia

2017

“…It is an established fact that change in temperature causes a change in the performance of the device, so an accurate knowledge of temperature dependent performance of the device is essential for its optimal use, especially in harsh environments . An improved knowledge of temperature dependent small signal equivalent circuit would play a key role in determining the device operating capabilities especially at high power and frequency . Different models have been developed so far to predict the temperature based performance of the device but, either they are too complex to handle or their accuracy deteriorates with increasing values of temperature.…”

Section: Introductionmentioning

confidence: 99%

An improved temperature dependent analytical model to predict AlGaN/GaN high electron mobility transistors AC characteristics

Khan

Ahmed

Rehman

2019

In this paper, an improved temperature dependent model has been presented to predict AC characteristics of submicron AlGaN/GaN high electron mobility transistors (HEMTs). The model evaluates effects of channel temperature on the device AC intrinsic parameters. It has been shown that the rise of channel temperature is almost linear in nature, and it depends upon both the ambient temperature as well as on the operating voltages of the device. By reassessing two dimensional electron gas (2‐DEG) carrier concentration, ns, high electron mobility transistor (HEMT)'s analytical I−V equations for both linear as well as saturation regions have been modified. The modeled DC characteristics showed a good degree of accuracy with the experimental data. By evaluating temperature and bias dependent charge accumulation in the depletion region of the device, an AC model for the device intrinsic parameters has been developed. S‐parameters of the device have been evaluated by using the modeled AC intrinsic parameters that showed a good agreement with the measured data. Thus, the developed technique could be a useful tool to predict AC parameters of submicron AlGaN/GaN HEMTs meant for harsh environments.

“…From Very High Frequency (VHF) to E-band systems, GaN relentlessly proves its vast potential for overcoming technological barriers and opening up new territories. [1][2][3] This special issue reports on the state-of-the-art, current challenges, and future prospects in the field of GaN transistor modeling. With the aim of ensuring a comprehensive treatment of the topic, different modeling techniques are addressed.…”

Section: Introductionmentioning

confidence: 99%

Guest editorial for the special issue on linear and nonlinear modeling of GaN transistors and circuits

Raffo

2016

SummaryThis Special Issue reviews the state-of-the-art and new trends in modeling of Gallium Nitride transistors. Aspects of transistor characterization, simulation, and design all receive significant attention, highlighting the potential of this disruptive technology in the development of future communication systems. KEYWORDSfield-effect transistors, Gallium Nitride transistors, linear and nonlinear measurements, microwave amplifiers, semiconductor device modelingThe future and success of new communication systems and services (eg, internet of things and long-term evolution) critically depends on the improvement of current and development of new technologies capable of supporting innovative uses of the frequency spectrum under increasingly stringent power constraints. This special issue is dedicated to one of the most important enabling microwave communication technologies of the past 2 decades: Gallium Nitride (GaN). Throughout the years, GaN has been a dominant force in supporting demanding new applications, oftentimes conquering fields once served by entrenched competing technologies (eg, Gallium Arsenide and laterally diffused metal oxide semiconductor). From Very High Frequency (VHF) to E-band systems, GaN relentlessly proves its vast potential for overcoming technological barriers and opening up new territories. [1][2][3] This special issue reports on the state-of-the-art, current challenges, and future prospects in the field of GaN transistor modeling. With the aim of ensuring a comprehensive treatment of the topic, different modeling techniques are addressed. In particular, physics-based numerical models 4 that provide a clear understanding of the most essential physical mechanisms that govern a device's operation, and compact models (eg, equivalent-circuit and behavioral descriptions) that permit the cost-effective design of advanced microwave circuits under nonlinear 5-9 and linear 10-13 operation, receive significant attention. Without a doubt, this special issue demonstrates the fundamental and unique role GaN transistor modeling plays in the conceptual development and design of new communication systems.In addition to the aforementioned topics, significant emphasis also is placed on state-of-the-art measurement techniques.14,15 Indeed, accurate model extraction necessitates the operation of transistors under realistic conditions that depend on the targeted application (eg, amplifier, mixer, and switch) as well as the investigation of device performance under operating conditions (eg, pulsed-bias) capable of exposing nonideal trends and behaviors that have to be accurately accounted for (eg, thermal and trapping effects). Sprinkled throughout the special issue, the reader will find interesting hints as to how advanced nonlinear models can be successfully adopted for designing novel microwave circuits. I would like to extend my gratitude and appreciation to all of the authors for their high quality contributions and to all of the reviewers for devoting their valuable time and expertise to improving ...