The AB-900A is a broadband, linearly polarised Biconical Dipole Antenna, operating over the frequency range of 25 MHz to 300 MHz. It can be used as either a receiving antenna (for EMI measurements) or as a transmitting antenna (for immunity tests) for power levels up to 50 watts.

Construction

The antenna elements are constructed using a corrosion resistant aluminium, which is powder coated for additional durability. Implemented in the element design is a “gamma match” rod, which connects the element’s centre rod to one of the outer elements at the inside edge of the 90 degree bend. The gamma match is necessary in order to avoid a significant “dip” in the antenna’s performance which would otherwise be present between approximately 275 and 290 MHz.

Application

The AB-900A Biconical Antenna is intended for use as an EMI test antenna for qualification-level regulatory compliance measurements (FCC, CE, MIL-STD-461, RTCA DO-160, FDA, SAE Automotive, etc.).

The AB-900A can also be used in conjunction with an RF power amplifier (up to 50 watts) to generate RF fields associated with radiated immunity testing.

In addition, a pair of AB-900A Biconical Antennas can also be used for Normalised Site Attenuation (NSA) calibrations of Open Area Test Sites (OATS) or Semi Anechoic Chambers (SAC) using the Geometry Specific Correction Factors (GSCF) given in Tables G.1 through G.3 of ANSI C63.5, as its physical dimensions conform to the minimum and maximum values given in Figure G.1 of ANSI C63.5 (Dimensions of biconical dipole antennas evaluated for numerical correction). If biconical antennas have dimensions which do not conform to these dimensions, the given GSCF values can not be used, and would need to be determined by performing GSCF calibration on a Standard Antenna Calibration Site (SACS) as described in Annex H of ANSI C63.5.

Notwithstanding the above applications, the AB-900A can also be used for test site comparisons, shielding effectiveness tests of large enclosures, field monitoring, site surveys and other general purposes.