270-GHz LTCC-Integrated Strip-Loaded Linearly Polarized Radial Line Slot Array Antenna

A planar linearly polarized radial line slot array (RLSA) antenna is proposed to achieve a high gain with improved impedance matching and suppressed cross-polarization levels at a 270-GHz band. The proposed antenna is integrated in low-temperature cofired ceramic (LTCC). The impedance matching is enhanced by loading each radiating slot individually with a strip pair and employing an integrated feeding transition to an external standard waveguide in measurement. The cross-polarized radiation level is suppressed at all directions by aligning the orientations of the radiating slots. The antenna prototype exhibits the measured |S₁₁| less than -10 dB over the frequency band of 261.3-282.2 GHz, a maximum boresight gain of 27.6 dBi at 275.2 GHz, and a 3-dB gain bandwidth of 9.8 GHz (271.2-281 GHz).