Foetal Alcohol Spectrum Disorders (FASD) develop when unborn children are exposed to alcohol prenatally. As a result of this exposure, children with FASD exhibit a range of social, behavioural, cognitive and even physical deficits that can impede their life-long development. These deficits can be influenced by maltreatment and the instability resulting from being placed into out-of-home care, and/or multiple foster-care placement breakdowns. The aim of this article is to increase awareness amongst child welfare professionals of how prenatal alcohol exposure impacts on children's social development. Social deficits include problems with social cognition and social information processing, which result in issues in social problem solving, processing social cues, social judgement, and developing and maintaining relationships. These deficits leave children with a FASD vulnerable to victimisation, exploitation, peer pressure and, as a result, interaction with the criminal justice system. Deficits are life-long and become more pronounced with age, although early detection and intervention appears to improve social skills deficits. Such interventions need to be explored further as they could potentially mitigate some of these deficits by capitalising on the neuroplasticity of a child's developing brain and pave a more positive trajectory for these children's future.

This paper presents a design method of internally-matched packaged GaN high electron mobility transistors (HEMTs) for achieving not only high-efficiency and high-power performances but also a wide bandwidth and insensitivity to harmonic terminations in the S-band. The package and its internal matching networks are synthesized to confine the second harmonic impedances seen by the GaN die to high-efficiency regions whatever the harmonic impedances presented outside the package. This paper reports the design of a packaged GaN HEMT achieving 78% of power-added-efficiency (PAE) and 25 W of output power at 2.5 GHz. A packaged GaN power bar is also reported with the addition of fundamental matching networks inside the package. In 50 Ω environment, the packaged GaN power bar provided more than 56% of PAE from 2.5 to 3.1 GHz and was desensitized to harmonic load variations with less than two points of PAE variation when a load-pull is performed at second harmonic frequencies outside the package.

We present an overview on epitaxial growth, processing technology, device performance, and reliability of our GaN high electron mobility transistors (HEMTs) manufactured on 3- and 4-in. SiC substrates. Epitaxy and processing are optimized for both performance and reliability. We use three different gate lengths, namely 500 nm for 1–6 GHz applications, 250 nm for devices between 6 and 18 GHz, and 150 nm for higher frequencies. The developed HEMTs demonstrate excellent high-voltage stability, high power performance, and large DC to RF conversion efficiencies for all gate lengths. On large gate width devices for base station applications, an output power beyond 125 W is achieved with a power added efficiency around 60% and a linear gain around 16 dB. Reliability is tested both under DC and RF conditions with supply voltage of 50 and 30 V for 500 and 250 nm gates, respectively. DC tests on HEMT devices return a drain current change of just about 10% under IDQ conditions. Under RF stress the observed change in output power density is below 0.2 dB after more than 1000 h for both gate length technologies.