A modified meandered structure with pentagon DGS and rectangular resonators for multiband wireless communication

This work presents a compact multiband microstrip antenna implemented on a low-cost FR4 substrate with dimensions of 40 × 35 × 1.6 mm. The design includes a modified meandered patch structure, a pentagon-shaped defected ground structure, and parasitically coupled rectangular resonators to realise stable multiresonant behaviour. It exhibits five operating bands at 1.37 GHz (GPS-L1), 3.53 GHz (WiMAX/5G-n78), 4.36 GHz (Cband), 4.96 GHz (WLAN-5 GHz), and 5.64 GHz (UNII-2C/5G unlicensed) with return-loss depths up to -21.7 dB. The addition of the modified meandered line increases the effective current path. The pentagon DGS and rectangular resonator further enhance impedance bandwidth and resonance selectivity. Prototypes simulated and fabricated show that the resonance occurs within a deviation of 2-4%, hence validating the close agreements. Compact size, multiband response, and stable radiation characteristics make this antenna suitable for portable devices, Sub-6 GHz 5G terminals, IoT units, and WLAN systems.