Antenna spacing and diversity

In this article we will discuss antenna spacing and diversity, and why it is important.

Antenna Diversity

Antenna diversity is used to improve signal reliability and reduce dropouts caused by interference, reflections, or obstructions. It is when you have two antennas, instead of one, receiving the same signal.

Wireless mic signals can suffer from:

• Multipath interference (signal reflections causing phase cancellation)
• Dead spots (areas with weak signal due to obstacles or interference)
• Movement of performers (changing signal paths)

How does it work:

• Two antennas are spaced apart (or oriented differently).
• The receiver constantly monitors both and chooses the one with the strongest signal.

What Are the Benefits:

• Fewer dropouts
• Better performance in challenging RF environments

Antenna Spacing

Maintain Line of Sight:

•  Antennas should have a clear line of sight to the transmitters whenever possible.

Space Antennas Apart: Omni Directional antennas

• Minimum spacing: At least 1/4 wavelength apart.
• Ideal spacing: Around 1/2 to 1 full wavelength apart.
• So, antennas should be spaced 10–20 inches apart.

Reasoning: Since they pick up signals from all directions, they are more prone to multipath interference. Closer spacing is acceptable, but diversity is still important.

Space Antennas Apart: Directional antennas

• Minimum spacing: At least 1 wavelength apart.
• Ideal spacing: 1.5 to 2.5 wavelengths apart to reduce coupling and improve diversity.
• So, antennas should be spaced approximately 30–60 inches apart.

Reasoning: Because of their directional focus, wider spacing helps ensure each antenna receives a different signal path, improving diversity and reducing dropouts.

For more information please visit: https://www.sennheiser.com/