A Wideband High-Efficiency Side-Connected Magnetoelectric Dipole Antenna Array Using Novel Feeding Technology for W-Band

In this communication, a wideband and high-efficiency <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8\times 8$ </tex-math></inline-formula> antenna array is proposed for W-band. This antenna array is composed of three parts: the magnetoelectric (ME) dipole radiating elements, the feeding structure for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 2$ </tex-math></inline-formula> subarray, and the feeding network. The proposed high-performance ME-dipole element has side connections on both sides of the two radiating patches, forming a dumbbell-shaped slot in the middle. This novel structure contributes to wide bandwidth (BW), high efficiency, and manufacturing suitability in high frequencies around 100 GHz. Moreover, each <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 2$ </tex-math></inline-formula> ME-dipole subarray is excited through four aperture-coupled slots right below the ME dipoles. The main part of the proposed feeding structure is a resonant cavity with a metal bar arranged in the middle to divide the waves, significantly improving the impedance BW of the subarray. The proposed feeding network exploits novel U-shaped T-junctions with improved low-frequency performance for widened BW. Finally, a cooperate ridge gap waveguide (RGW) feeding network is employed to feed the whole <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8\times 8$ </tex-math></inline-formula> antenna array through coupling slots right below the cavities. To verify the design, a prototype of the proposed antenna array is fabricated and measured. A measured BW of 28.5% from 81.5 to 108.6 GHz with a maximum gain and a radiation efficiency of 26.6 dB and 86.8% are achieved. The proposed antenna array has significant potential in W-band applications, such as high data-rate communication, high-gain detection, and high-resolution imaging systems.