Linear Tapered Cavity-Backed Slot Antenna for Millimeter-Wave LTCC Modules

In this letter, a linear tapered slot antenna (LTSA) which is backed by an air cavity is proposed and fabricated using low temperature cofired ceramic (LTCC) substrate. Traditionally, the high dielectric constant and the thick LTCC substrate seriously degrade the gain and radiation property performance because a large portion of the radiated fields are confined in the LTCC substrate. However, the proposed LTSA with the air cavity backing structure exhibits a high gain (4.9-6.9 dBi) and a good end fire radiation pattern. Also, the proposed antenna has a wide impedance bandwidth (about 30 from 45 to 75 GHz). Through numerical and experimental analyzes, we found that the proposed antenna can be used for a variety of millimeter-wave applications, due to its broadband operating range and its easy integration with 3-D LTCC module.