Bicone Antenna: Function and Basics

Most microwave antennas are directional. However, many applications require omnidirectional antennas. The key difference is that directional antennas radiate electromagnetic (EM) waves in a specific direction, while omnidirectional antennas radiate in all directions.

For example, a simple dipole antenna is omnidirectional, whereas a horn antenna is directional.

Fig.1 Bicone Antenna

One of the most popular omnidirectional antennas is the Bicone Antenna. The figure above illustrates its setup.

The signal is fed to the antenna through a circular waveguide. This waveguide terminates in a flared cone. Another cone is attached above the lower one. This upper cone acts as a reflector, helping to radiate the EM waves equally in all directions. Bicone antennas generate a very narrow vertical beam width.

Advantages of Bicone antenna

Following are some of the main benefits of bicone antenna.

1. They are broadband by nature which covers decades of frequency ranges.
2. Provides 360 degree coverage in horizontal plane.
3. Due to its structure, it is mechanically simple and easy to fabricate.
4. Offers constant impedance over its operating range.
5. Due to flat frequency response and wide bandwidth, it is commonly used for EMI/EMC test setup.
6. Suitable for mobile and surveillance applications.
7. It does not require re-tuning or complex matching networks when switching between bands.