A family of standard gain horn antennas for electromagnetic interference (EMI) and electromagnetic compatibility (EMC) testing applications covers every waveguide band from 2.6 to 40 GHz. Specifically, the 600 series horn antennas include seven standard models spanning 2.6 to 3.95 GHz, 3.95 to 5.85 GHz, 5.4 to 8.2 GHz, 8.2 to 12.4 GHz, 14 to 18 GHz, 18 to 26.5 GHz, and 26.5 to 40 GHz. All of the models offer directivity patterns including a beam width in the E and H planes from 23 deg. at 40 GHz to 34 deg. at 2.6 GHz. They provide side lobes in the H plane that are more than 20 dB down from the main response while first side lobes in the E plane are 13 dB down and second side lobes are 18 dB down. At mid-frequency, the horn antennas offer 16.5 dBi gain 1.5 dB over the operating bandwidth. All of the models feature a voltage standing wave ratio of 1.15:1 or less. They weigh anywhere from 6 lbs. for the 2.6-to-3.95-GHz model to 4.5 g for the 18-to-40-GHz model. The 600 series horn antennas are supported by a variety of waveguide-to-coax adapters for either Type-N female or SMA/3.5/2.9-mm female connectors. All models are available for immediate delivery.