The EH1840 antenna is single linearly polarized antenna that combines stable gain performance, low VSWR, and excellent cross-polar discrimination with wide band frequency operation. The unique horn design suppresses any possible excitation of higher order modes in the aperture and maintains a well-defined smooth radiation pattern in the direction of the boresight axis throughout the operational bandwidth. The design uses a corrosion resistant aluminum and high reliability manufacturing technology, making for a lightweight, durable horn that has excellent performance repeatability. The horn is equipped with a high precision female K connector for superior repeatability and durability. The The EH1840 Dual-Ridge Horn antenna is applicable for EMI testing as per FCC and MIL-STD-461 standards, as well as other applications. It is calibrated at a 1 m distance as per SAE ARP 958.