Low-profile broadband aperture coupled magneto-electric dipole array antenna for millimetre-wave applications

This Letter presents a low-profile broadband cavity-backed magneto-electric (ME) dipole antenna fed by a substrate integrated waveguide aperture. To reduce the antenna profile, a U-shaped slot is etched on the electric dipole. Compared to the traditional ME dipole antenna whose profile is generally 0.25 lambda epsilon, the thickness of the proposed radiation structure is 0.13 lambda epsilon, where lambda epsilon is the wavelength in the dielectric substrate. A 4x4 array antenna with the proposed antenna as its element is then designed, simulated and fabricated. With the return loss is below -10 dB, a 19.1% (30.3-36.7 GHz) impedance bandwidth has been achieved. The radiation pattern of the proposed array antenna is quite stable, and the peak gain varies below 1 dB within the operating band.