A Broadband Double Ridged Horn Antenna for Radiated Immunity and Emissions Test from 18 GHz to 50 GHz

This paper presents a new type of double ridged horn antenna design for both radiated immunity and emissions test of broadband applications in EMI measurement. The proposed antenna offers excellent performance over the frequency range of 18 to 50 GHz as required by the EMI regulation compliance tests (i.e. FCC, CE, MIL-STD-461, RTCA DO-160, FDA, SAE, etc.). The optimized antenna aperture dimension of flared section of pyramidal structure and improved the ridge profile are yielded the wide antenna beam-width across the bandwidth, lower VSWR, stable gain and symmetric radiation patterns with low side lobe level. Moreover, a coaxial probe structure in the feed section and fitted with by a 2.4 mm connector, while under the increased bandwidth for good impedance matching. To achive the charactistic of this well designed antenna, whose has been implement, measurement, and to reduce the difficulty and cost of daily use in laboratory environments for a standard semi-anechoic chamber.