Ultrawideband 3-D Printed Endfire TEM Horn Antenna Mounted on a Cylinder Conductor

An ultrawideband, 3-D printed endfire transverse electromagnetic (TEM) horn antenna mounted on a cylinder conductor is proposed. The system consists of four TEM horn antennas and a cylinder conductor. The proposed TEM horn antenna is composed of four parts: a metal exponential curve, a trapezoidal metal top cover, a cylindrical ground, and a metal ridge. To enhance impedance bandwidth and radiation characteristics, a metal ridge is introduced on the cylinder ground plane. To verify the proposed antenna, a prototype is 3-D printed with surface metallization. The proposed antenna has a broad bandwidth from 1 to 16 GHz (16:1) with a voltage standing wave rate <2 and a profile of 0.134 ${\lambda }_L$ ( ${\lambda }_L$ being the free-space wavelength at the lowest frequency). A good radiation pattern is obtained over the impedance bandwidth, and the measured gain ranges from 3.5 to 11.5 dBi.