Researchers have unveiled a cutting-edge 8 × 8-element slot antenna array optimized for applications within the 30 GHz band, showcasing remarkable performance attributes and innovative design features.
This antenna array addresses the surging demand for higher data throughput within modern communication systems, particularly benefiting satellite communications. With the growing use of spot-beam coverage and increased spectral availability, antennas operating efficiently at higher frequencies have become increasingly indispensable.
Notably, the array boasts high gain, exceeding 23 dBi, and achieves wide impedance bandwidth with approximately 33% coverage across the 25-to-35 GHz range. This is largely attributable to its pin/hole design, which offers substantial advantages over traditional fabrication methods, primarily by simplifying the process and reducing costs.
The feeding network, crafted with precision, features arrays of pins and guiding ridges integrated within the metal plate. This configuration facilitates efficient power distribution to the radiative elements. A double transition from ridge waveguide to rectangular waveguide ensures seamless operation, leading to efficient connections with standard 2.92 mm coaxial connectors.
During the validation process, experimental results confirmed the theoretical findings. The measured bandwidth maintained impedance matching coefficients |S11| below -10 dB, effectively demonstrating the reliability and efficiency of the 8 × 8 slot antenna array.
This design's simplicity directly correlates with its effectiveness. It minimizes RF leakage along the lines by employing multi-layer pin/hole shielding mechanisms, eliminating the need for electrical contacts between different layers of the multi-layer antenna structure. Such innovations pave the way for new standards within satellite communication technologies.
Through CNC milling, the prototype was produced with precise dimensions of 64 × 84 mm² and total thickness of 23 mm. This compact design reinforces its viability for commercial applications where size and performance are pivotally important.
Measured performance metrics consistently demonstrated gains exceeding 22 dBi across the 25–35 GHz bandwidth, with variation only reaching 2 dB, which is exceptional for antennas used within this frequency range.
Alongside high gain and bandwidth, the antenna demonstrates efficiency levels nearing 70% across the bandwidth, marking it as a formidable competitor among high-frequency antennas.
Challenges associated with discrepancies between simulated and measured gains primarily stemmed from external factors, including reflection and loss due to the surface irregularities affecting metal conductivity. Such factors can impact performance, especially as antenna dimensions approach free-space wavelengths.
The E-plane sidelobe levels averaged around -9 dB, indicating satisfactory performance, whereas the first sidelobe levels observed in the H-plane were approximately -18 dB. Measured results over various planes showcased extraordinary potential for future applications, all the more so considering the factor of mechanical tolerances during manufacturing.
This new 8 × 8-element array design exemplifies the strides made toward meeting the burgeoning needs of satellite systems. Efforts such as achieving compact designs with effective performance metrics play pivotal roles as communication technologies advance to meet user demands.
With impeccable validation results and comprehensive design methods, the research paves the way for future antenna systems geared toward higher-frequency operations with enhanced efficiency and performance. The authors note, "The measured outcomes show an impressive 33% impedance matching bandwidth (|S11| < -10 dB) across the 25-to-35 GHz frequency range"—a conclusion underscoring the significance of this innovative design.
This cutting-edge 8 × 8-slot antenna array introduces new possibilities within satellite communications, helping to shape the future of efficient and compact antenna structures for high-frequency applications.