The SBA 9113 B design is based on the popular SBA 9113, but with a balun modified for low-frequency operation down to 80 MHz. The outstanding high-frequency performance of the 9113-balun could be preserved combined with a remarkable extension for low frequencies. Therefore the SBA 9113B can be used as a frequency selective field probe for immunity testing, e.g. according to IEC 61000-4-3 in combination with a spectrum analyzer or an EMI-receiver. A field strength of 1 V/m leads to receiver readings of 60-95 dBμV, depending on the frequency. Although the SBA 9113B can be connected directly to receivers up to field strength levels of 30 V/m, we generally recommend the use of a fixed pad at the antenna connector. This provides a better measurement accuracy because of better impedance matching and helps to shift the output level in suitable ranges even for the highest field strength levels.

Application

The typical applications of the microwave biconical Antenna are the evaluation of test sites, the (frequency selective) field strength measurement, and the generation of defined field strength (e.g. ERP or EIRP). Thanks to the wide bandwidth there is no need for a time-consuming change of the antenna elements as required when operating with tuned half-wave dipoles. The biconical elements allow a continuous sweep over the complete frequency range. Because of the dipole-like directional pattern, the fixed phase center and the high power handling capability the SBA 9113 B may replace tuned half-wave dipoles in many applications. The SBA 9113 B is not intended for emission testing with very low limits, horn, and Log.-Per. Antennas are better matched for this purpose because of their better antenna factor. A typical application of SBA 9113 B is the determination of the field strength-exposure near base stations in the GSM-bands.

The small biconical elements come with a male M4 thread, which fits into the element fixture nuts of the balun. When mounting the biconical elements care should be taken in order to avoid overtightening the threads. It is absolutely sufficient to tighten the elements with two fingers. Various experiments have shown that the contact at the feed point is always sufficient.