Ground Radiation Based Triple-Band MIMO Antenna with Wideband Characteristics for Wi-Fi and Wi-Fi 6E Applications

The paper presents a ground radiation antenna (GradiAnt) based triple-band MIMO antenna with wideband characteristics for Wi-Fi 6E applications. The GradiAnt is a novel antenna element with a series combination of inductor and capacitor in the feed loop, and dual-band characteristics have been achieved by controlling the impedance level of the antenna. By introducing a parasitic resonator within the feed loop of GradiAnt, triple-band characteristic is achieved, and significant bandwidth enhancement is realized, fully covering the Wi-Fi and Wi-Fi 6E operation bands. The resonator consists of a parasitic strip connected with the ground plane through an inductor. Two identical GradiAnts are symmetrically installed at the corners of the shorter edge of the 55 × 40 mm² sized ground plane for MIMO scenarios. A loop-type isolator is installed between the antenna elements to decouple the lower Wi-Fi band where the higher bands are self-isolated. The measured bands with reference to −6 dB are 2.36–2.63 GHz and 4.76–8 GHz. The isolation in the lower and higher bands is greater than 22 dB and 17.5 dB, respectively. The ECC is less than 0.03 in the lower band and 0.16 in the higher bands.