MILLIMETER-WAVE RECTANGULAR WAVEGUIDE-BASED SLOTTED ANTENNA

Abstract

The slotted waveguide antenna array has been widely used for many decades in military radar systems and also found in many nonmilitary applications such as remote sensing, weather radar, navigation, radio links and several other communication systems. This work uses multiple layers of mechanically machined metal contours to assemble a Ka-band (26.5GHz to 40 GHz) WR28 standard rectangular metal waveguide - based slotted antenna. A total of 16 slots along the length of the waveguide is designed to obtain a maximum measured gain of 14 dBi along the broadside direction. To combat the inherent feature of low impedance matching bandwidth of such antennas, a shunt stub - based matching technique is implemented. The measured input reflection coefficient is better than -10 dB over 5% bandwidth at a center frequency around 31.4GHz with an estimated efficiency of 85%. Also in this work, the single ridge waveguide has been explored to acheive the optimum radiation pattern with low side lobe levels by availing from the features of ridge waveugide and applying non-uniform slots configruation. Consequently, this work not only contributes to the advancement of antenna technology but also opens avenues for future research in the field of high-frequency communication systems.