Tunded Dipole Antenna

Antenna Symmetry

Some antenna manufacturers add an unsymmetrical crosspiece to the bicohnical elements in order to solve the inherent dip at the upper frequency response. Our solution is a simple ferrite around the center post of the elements, thus eliminating changing the symmetry of the antenna. The superior symmetry of the SAS-540 biconical antenna meets the ANSI C63.5-2017 symmetry requirements.

Antenna VSWR

One drawback to the biconical antenna design is the poor VSWR especially below 80 MHz. This is due to the limited size requirements spelled out in MIL-STD 462 and can be overcome by the selection of a larger element set. Another way to overcome this short fall is to add a 3 or 6 dB attenuator, this will improve the VSWR in the order of 2:1 or even better.

Radiation Pattern

The radiation pattern is a chart of the variation of the field intensity of an antenna as an angular function with respect to the axis. The radiation pattern of the biconical antennas are similar to the half-wave dipoles. They have an omni-directional response in the H-plane, and a figure eight shape in the E-plane. The H-plane beamwidth pattern makes these antennas ideal for field survey and spectrum monitoring.

Half-wave tuned dipole antenna showing
quarter wavelength element with respect to a wavelength.

• Applications/Test Type: Rasiated Emissions, Military EMC, Precompliance EMC
• Markets:
• Test Standards: FCC, CISPR, MIL-STD