Cost-Effective Surface-Mount Off-Center-Fed Dipole Antenna Element and Its Array for 5G Millimeter Wave New Radio Applications

Abstract

A cost-effective ball grid array (BGA) packaged surface-mount off-center-fed dipole antenna element and its array are proposed for 5G millimeter-wave new radio (NR) applications. The proposed antenna element exhibits a compact size of 0.61 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×0.61 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×0.16 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ( λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the wavelength in free space at the center operating frequency) and is realized by only one FR4 layer to minimize cost. Plated through holes (PTHs) connect the dipole patch on the top layer to the bottom layer. Furthermore, tin-lead solder balls are mounted under the bottom layer to form the BGA packaging. The surface-mountable feature enables the antenna element to be integrated with other surface mount devices without any waveguide or coaxial connectors. The evaluation board uses a 50- Ω grounded coplanar waveguide (GCPW) line to test the performance of the antenna element and array. The antenna prototype and evaluation board have been manufactured and measured. The measurement results show that the -10-dB impedance bandwidth of the proposed antenna element achieves 35.7% in the range of 25.1-36 GHz. The measured peak gains of the antenna element and the 1 ×8 arrays are 6.72 and 13.53 dBi, respectively.