This is because the signal could reach people who live near the house and use it to gain internet access without the knowledge of the individuals who purchased the unit. Antennas come in different sizes and shapes. Instead, it is intended to provide an insight to the key elements of the mobile phone technology which would otherwise remain invisible to everyday users.

More commonly, the impedance is adjusted at the load with an aerial tuner, a balun, a matching transformer, matching networks composed of inductors and capacitors, or matching sections such as the gamma match. If an external HDTV antenna is not an option, perhaps because you live in an apartment or in a building of historic interest, then you'll have to go for an internal, set-top aerial.

Your handset and provider: If you put features to one side, one handset works in much the same way to any other and the same is true of the actual network provider you choose to go with. Unfortunately, every HDTV antenna is not alike and the quality of your picture can vary greatly depending on which antenna you choose.

In this article I'll try to do just that - simplify the technology. If you move location, and your original antenna no longer has enough reach to connect to your mobile, your phone will automatically search for another one. The radiation pattern is perpendicular to the plane of the loop, with sharp nulls in the plane of the loop. As with any item of electronics, the key is to do your research. One of the goals of aerial design is to minimise the reactance of the device so that it appears as a resistive load.

A trailing wire aerial is used by submarines when submerged. The microstrip aerial consists of a patch of metalization on a ground plane.

Impedance, however, is not applied in an obvious way; for impedance, the impedance at the load is most critical. Variations of the dipole include the folded dipole, the half wave antenna, the groundplane aerial, the whip, and the J-pole. Typically, a random wire aerial will also require an antenna tuner, as it might have a random impedance that varies nonlinearly with frequency. As such, it is less sensitive to near field electric noise when properly shielded.

The greater the ratio of radiation resistance to ohmic resistance, the more efficient the aerial. Wavelengths get so short at these frequencies that it is not possible anymore to transmit using a pole aerial and transmit in all directions.

The result is that energy is continually radiated into space, and must be replenished from the circuit's power supply. Generally, antenna gain is increased without changing aerial size by narrowing the aperture to increase power density in a single direction while reducing it in all other directions.

Reactance can be eliminated by operating the antenna at its resonant frequency, when its capacitive and inductive reactances are equal and opposite, resulting in a net zero reactive current. This results in higher frequencies having shorter wavelengths.

Antennas have practical use for the transmission and reception of radio frequency signals, which can travel over great distances at the speed of light, and pass through nonconducting walls. Often a dipole is also used as a practical reference as the isotropic source cannot be realised in practice, but it has 2.1 dB gain over an isotropic source.