What is antenna beamwidth coverage calculator? 

In antenna theory, Half Power Beam Width (HPBW) refers to the angular separation θ (in degrees) between two points on either side of the main lobe of the antenna's radiation pattern, where the power drops to half (50% or -3 dB) of its peak value (see Figure). These two points are referred to as the half-power points. HPBW helps define the beam's directivity and the area it covers as it radiates. 

Antenna Beamwidth Coverage Calculator is an online tool used to estimate beamwidth (i.e., spot size) covered (in meters) by an antenna's beam at a specific distance. This calculator works by inputting the antenna half-power beamwidth (in degrees) and the product separation (P.S.) distance (in meters) from the antenna. 

In EMC immunity testing, product separation distance refers to the distance between the antenna and the device under testing. The Beamwidth coverage (spot size) can be increased by either increasing the separation distance (d) or using an antenna with a large half-power bandwidth. 

This calculator is especially useful for understanding how much beamwidth coverage (wide a spot size) an antenna's signal will cover at a certain distance, which is critical in designing antenna systems for applications such as EMC testing, wireless communications, radar, and more. 

The calculator typically uses the following formula: 

Where: 

d - product separation distance (in meters). It is the distance from the antenna to the product under test in the context of EMC testing. 

S - beamwidth coverage (or spot size) at the product separation distance (d) from the antenna (in meters). 

θ - antenna half-power beamwidth angle or 3dB beamwidth angle (in degrees) 

Example calculation: If the product distance (d) is 1 Meter and half-power beamwidth is 30 degrees, calculate the antenna beamwidth coverage.  

Solution: By substituting d = 1 m and θ = 30 degrees in the above formula, we get: 

Antenna beamwidth coverage S = 0. 536 Meter.