Low-Profile Thin End-Fire Antenna Array Element with Parasitic Layers

This paper presents the design steps of a PCB based low-profile, thin end-fire antenna array element which offers low air drag. The design is started with a linearly polarized top-loaded monopole antenna placed on the middle layer of a printed circuit board, then two reflector elements are added to the back of the driven spherical antenna on the same layer in order to achieve an end-fire radiation characteristic. Then two parasitic layers are added to the outer layers of printed circuit board to widen the impedance bandwidth. Finally, two lumped elements are placed between antenna and its coaxial connector to improve antenna matching. Final design has approximately 17% 10 dB reflection coefficient bandwidth and 6 dBi realized gain at the center frequency. Dimensions of final design are <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.79\lambda_{0}(\text{length})\times 0.01 \lambda_0(\text{width }) \times 0.125 \lambda_0(\text{height })$</tex>. Proposed end-fire antenna is used in infinite linear array and its active s parameter performance is investigated.