Design and validation of A 30 ghz 8 × 8 slot antenna array with ridge waveguide pins/holes layers

This paper presents an 8 × 8-element slot antenna array optimized for 30 GHz band applications, achieving high gain, wide impedance bandwidth, and high efficiency. The array employs a pin/hole-based design, which enables a compact structure and reduces fabrication complexity and cost, as it eliminates the need for electrical contact between its three primary layers: the metal radiating slot plate, a sub-array cavity layer, and a ridge waveguide feed network layer. The corporate feed network is realized through an array of pins and guiding ridges integrated into a metal plate, effectively distributing power to the radiating elements. A double transition from ridge waveguide to rectangular waveguide, leading to a 2.92 mm coaxial connector, ensures efficient feeding. Each component, including the radiating elements, cavity layer, power dividers, and transitions, is designed and optimized to maintain a low reflection coefficient (|S₁₁| < -10 dB) across the 25-35 GHz frequency range. The 8 × 8 array is fabricated using standard milling techniques. The measured impedance matching bandwidth of approximately 33% is obtained, covering the entire 25-to-35 GHz range. The array consistently demonstrates a gain of over 23 dBi validating its performance for high-frequency applications.