Electromagnetic compatibility (EMC) is an essential part in today’s society and there are more products around us that emit electromagnetic waves than ever before. To make sure that all these products function properly under all circumstances EMC testing is needed. One test that is conducted is radiated immunity testing. A susceptibility antenna is needed to perform immunity testing. This thesis aims to show that a tuneable antenna could be used for immunity testing in the frequency band 26-150 MHz and in the future replace the current antenna, which is not tuneable, used at SAAB Support and Services EMC in Östersund. A simulation program called EZNEC+ was used to simulate different antennas that were tested in the semi-anechoic chamber at SAAB. Two antenna types showed better efficiency and reached lower in frequency than SAAB’s current antenna. These antennas were a bowtie antenna and an x-shaped antenna, both extending in only two spacial directions instead of the normal three. Their drawback was a less uniform E-field at the lowest frequencies, where the E-field was much stronger to the sides compared to straight in front of the antenna. This results in a narrow lobe width, but if this drawback could be accepted or mitigated both antennas are possible replacements for the current antenna at SAAB and should be further investigated.