antenna

A type of antenna formed by a coiled small-diameter spring, usually covered in plastic and somewhat flexible. Physically shorter than a standard 1/4-wavelength whip antenna, but also considerably less efficient.

A single element antenna that can be directly attached to a wireless transmitter or receiver. The short flexible antennas found on handheld two-way radios and cell phones are examples of this type of antennas.

A type of directive antenna that provides moderate to high gain over a relatively limited frequency range. Commonly used in communications when the operating frequency is above 10MHz. This type of antenna is popular among Amateur Radio and Citizens Band radio operators.