In certain situations, an antenna with an omnidirectional radiation pattern is desirable. For instance, such a characteristic is typically preferred for an antenna in a transmitter application.
Recent developments in the antenna art have produced several types of antennas capable of providing a horizontally polarized omnidirectional radiation pattern. For example, one type is an Alford loop strip antenna and a turnstile antenna, which are constructed from two dipole antennas. However, such antennas usually have larger sizes in transverse cross-section. Therefore, there is still room for improvement in the above techniques.