Printed antennas for millimeter-wave applications

In this paper, we introduce three printed wideband antenna designs for millimeter-wave applications. They are (1) U-slot loaded patch antenna, (2) vertical patch antenna, and (3) magneto-electric dipole antenna. This work is to demonstrate how to use printed element, plated-through-hole element and their combination to develop wideband antennas at millimeter-wave frequencies. The first example performs a directional radiation from a printed radiating patch with a wide impedance bandwidth of 33% (for reflection coefficient <; -10 dB) and a maximum gain of 7 dBi. The second design realizes a broadside radiation from a vertical via-hole embedded in a microwave substrate. This antenna has the impedance bandwidth of 50% and obtains a maximum gain of 9 dBi. Finally, the third antenna comprises of printed and plated-through-hole elements to obtain a directional radiation pattern with low cross polarization level, low back radiation, and stable antenna gain across the operating bandwidth. The antenna yields an impedance bandwidth of 40% and a maximum gain of 8 dBi.