MILLIMETER-WAVE INTEGRATED-HORN ANTENNAS .2. EXPERIMENT

The impedance and radiation patterns of a dipole-fed integrated horn antenna in a ground plane are experimentally investigated at microwave and millimeter-wave frequencies. The agreement with the full-wave analysis technique presented in Part I is good. The results indicate that for a 70-degrees flare-angle horn, horn apertures from 1.0-lambda-square to 1.5-lambda-square with dipole positions between 0.36 and 0.55-lambda yield good radiation patterns with a gain between 10-13 dB, a cross-polarization level lower than -20 dB, and resonant dipole impedances between 40-OMEGA and 120-OMEGA. It is also found that the impedance measurements can be safely used for two-dimensional horn arrays, but the radiation patterns differ because of the Floquet modes associated with the array environment. The integrated horn antenna is a high-efficiency antenna suitable for applications in millimeter-wave imaging systems, remote-sensing, and radio astronomy.