Complementary Split Ring Resonator loaded Proximity Coupled Triband Antenna for Sub-6 GHz Use Cases

This article highlights a triband proximity coupled antenna for 5 G, or sub-6 GHz use cases, that is equipped with a Complementary split-ring-shaped resonator (CSRR). Initially, a proximity coupled patch antenna is designed for 3.5 GHz. Next, a Diamond Shaped CSRR is etched on the bottom of the second substrate which gives rise to multiple resonant bands. The antenna is compact in size of $40 \times 50 \times 3.2 \mathrm{~mm}^{3}$. The triband antenna has characteristic resonances occurring at $2.4 \times 10^{9}$ and $3.5 \times 10^{9}$ and $5.4 \times 10^{9}$ frequencies with bandwidth of $60 \mathrm{MHz}, 110$ MHz and 172 MHz respectively. The antenna has a gain of 4.38 $\mathrm{dBi}, 6.43 \mathrm{dBi}, 6 \mathrm{dBi}$. The antenna is simulated using Computer Simulation Technology (CST). The antenna is suitable for sub-6 GHz use cases.