Gallium arsenide [device applications]

The device potential of GaAs and the problems inhibiting its widespread use are examined. Problems encountered in growing wafers are stringent process requirements for obtaining pure material, high susceptibility to lattice defects, small size (2-3 in) of wafers that can be grown, low thermal conductivity necessitating a special heat sink, and the uselessness of native oxide, which must be avoided during manufacture. With respect to the microelectronic properties, the speed of GaAs devices is much higher, with electron velocities measured up to five times that of comparable silicon devices. With very high transconductances and low input capacitances, GaAs devices can obtain much higher gain-bandwidth products (up to 15-20 GHz) that lead to switching speeds of up to 50 ps, about half the speed of silicon. However, this speed advantage erodes at high levels of integration, where costs demand simple and compact packaging. The reasons whey technologies available today for silicon devices-the bipolar junction transistors (BJTs) and field effect transistors (FETs), specifically the MOSFETs-do not work well for GaAs are examined, and new device technologies for GaAs devices-the metal-semiconductor field-effect transistor (MESFET) and the heterojunction bipolar transistor (HBT)-are described     

Controller area network [automotive applications]

The controller area network (CAN) is becoming a de facto standard for data transmission in automotive applications. Such applications are characterized by their obligation to respect stringent time and dependability constraints. This is why it is vital, at the design step, to validate their behavior. The verification is based on the performance evaluation of the operational architecture. The authors' approach involves: (1) building models (both analytic and simulation) and solving them (model-based evaluation); and (2) performing network monitoring on a prototype of the system (prototype-based evaluation). Automotive communications systems face an extremely hostile electrical environment (strong electromagnetic disturbances). To assume it is a 100% reliable medium is irresponsible in the face of such reality. So, the authors focus on transmission errors that may cause missed deadlines because of retransmitting corrupted frames. They propose using a flexible error-model for assessing the transmission's reliability and for designing well-suited message scheduling policies     

RF/microwaves [medical applications]

Radio frequency (RF) and microwaves have been used in many new applications in medicine, in the field of cardiology, microwaves are used to treat arrhythmias (abnormal heart rhythms) and blocked coronary arteries. Urologists use similar systems to treat obstruction of urine flow due to an enlarged prostate. RF is being used by ear-nose-and-throat specialists to treat airflow obstructions responsible for snoring and sleep apnea. In the future, surgeons may use microwave energy to assist in liposuction procedures and perform tissue welding. New applications are constantly under development. This article reviews how heat generated by RF/microwave energy is utilized to modify a variety of biological tissues     

An interesting phenomenon [lighting technology]

Before the tungsten filament bulb and the fluorescent tube disappear from the market, a very interesting phenomenon regarding their operation in a series is examined here. Reported by some electricians, the phenomenon is significant since it provides insight to the initiation of arc. Also, its maintenance is in a fluorescent tube with the help of a tungsten filament bulb instead of a choke.     

Charge of the electric car - [power electric vehicles]

This paper discusses the ability of the UK power grid to support the growth of electric cars has been called into question.     

Displays 2.0 [COMMS display technology]

Just as a nation of TV watchers finishes bolting their first flat panels to the living-room wall, a new set of display technologies is emerging to offer better image quality, bigger screens and thinner panels.