That antenna is based on
SD 5-23 HV antenna concept. Its radiator was modified by RFline to ensure best performance in frequency band 5.9-6.43GHz. Introduced modifications allowed to shift cut-off frequencies for higher modes up to 6.5 GHz. That is the obligatory condition to get high level of isolation between two orthogonal polarizations. New solution was fixed to cassegrain reflectors and tuned to obtain the best performance in defined frequency band. A huge effort was put to keep good parameters of the antenna also in 5.45-5.8 GHz band. Both antennas are comparable in that band.