In the subfield of electronics, electrical engineers construct models of electrical components (such as resistors, capacitors, inductors, transistors, diodes, semiconductors) for simulation purposes. They combine these components into larger electrical networks.
The subfield of power engineering deals not only with electricity generation, power transmission">electric power transmission and electricity distribution but also with electrical circuits and materials (e.g. insulators) that need to resist high voltages and currents.
Another subfield is accurate measurement of electrical properties. Measuring an electrical circuit inevitably changes the voltages and currents in it. The objective is to minimize the influence of the measuring circuit or even compensate for it. The field also includes sensors that use a material's electrical properties or electromechanical means of measurement. Examples of the former are piezoelectricity for measuring pressure and temperature-dependent resistors for measuring temperature. These sensors can be used in control engineering.
Other major subfields of electrical engineering are telecommunication and electromagnetism. Transmitting information from one place to another requires a transport channel such as a coax cable, optical fiber or free space. These channels can be accurately described using the laws of electromagnetism, particularly Maxwell's equations.
Some other examples of how electromagnetism is put to every day use are antenna design for use in mobile phones, and controlling the form of the electromagnetic field in an MRI scanner by the exact placement and alignment of its electromagnets. Another technology made possible by electromagnetism is the microwave oven. The field of high-power radio-frequency (RF) engineering was once feared to be a lost art. Because of the trend for low-power, miniaturized circuitry, there is a perception that the need for high-power radio engineering and engineers is diminishing. On the contrary, the need for engineers and technicians in this particular field has never been greater, and the need will only increase in the foreseeable future.
The tools and theories an electrical engineer can consult include mathematics and physics in general, the theory of electromagnetism, the theory of quantum mechanics, the mathematics of digital signal processing, control theory, the teachings of computer science.
Institute of Electrical and Electronics Engineers (IEEE) and the Institute of Electrical Engineers (IEE) are prominent non-profit organisations for electrical engineers that publish standards, publications and periodicals and organise conferences and workshops. The IEEE, in fact, is the largest professional organization in the world.
semiconductor device fabrication has led to the development of complete systems on a single chip, a process called Very Large Scale Integration. Microprocessors are a result of this evolution. This subfield spawned the related discipline of computer engineering.
Electronics that deal with both electrons (electricity) and photons (light) are also called optoelectronics. The related field of fibre optics has led to the development of fast telecommunication systems and the expansion of the Internet.
On the boundary of mechanical engineering and electrical engineering, mechatronics push the boundaries of what mechanical components can do. The precise positioning of the laser in a compact disc player to follow a track is only possible due to electronics designed to compensate for the vibrations, the loss of focus, the irregularities in the disc, etc.