Helical

A type of antenna characterised by its helix or spring-like shape, typically composed of a wire wound in the form of a screw thread. By adjusting the diameter, pitch, and number of turns of the helix, the antenna can be designed to operate efficiently at desired frequencies. It has a directional radiation pattern when used in the axial mode (with dimensions larger compared to the operating wavelength), making it suitable for applications requiring focused coverage such as in satellite communication. When used in normal mode (with dimensions smaller compared to the wavelength), it behaves similar to a short dipole, making it useful in applications where compactness is desired.