Meander-Line Monopole Antenna With Compact Ground Plane for a Bluetooth System-in-Package

Abstract

In this letter, a packaged compact meander-line monopole antenna for Bluetooth communications, manufactured in low-density fan-out technology, is presented. A combined size for the antenna and ground plane of $\bf 0.1\lambda _0\times 0.06\lambda _0\times 0.008\lambda _0$ is obtained. Such small antennas are usually designed considering their connection to an evaluation board with a large ground plane, which improves their gain and bandwidth, but in this letter, the antenna is designed so it can work standalone without any further connection to printed circuit boards. The challenge of designing such a compact antenna is surpassed by performing a detailed modeling of the radiating meander-line element altogether with its finite ground plane, a tuning inductor, and an inductive coupling feed. The antenna model is developed in Ansys HFSS using the finite element method, which is later validated experimentally. Measurements of the return loss radiation pattern are carried out, and final results show a $-$ 6 dB bandwidth of approximately 110 MHz and a gain of $-$ 8.7 dBi, at 2.42 GHz.