Quad-band Crown-Shaped Hairpin Antenna with AMC for WBAN and 5G Applications

An irregular, quad-band crown-shaped hairpin antenna with AMC-back is presented. The antenna consists of a crown-shaped radiation patch with a U-shaped slot and a defected ground structure (DGS). This configuration, with resonant frequencies at 1.44, 2.23, 3.98, and 4.49 GHz, will apply to the new generation of 5G/6G mainstream commercial bands (N77 and N79). By placing an artificial magnetic conductor (AMC) with three zero-phase bands in the reflection spectra, the gain at 4 frequency points increases by 1.2, 5.21, 5.4, and 6 dBi, respectively. The directional radiation pattern obtained from the developed antenna ensures low backward radiation to the body tissue. We also got the head data using the Fourth Cole-Cole Model and established a model to calculate the specific absorption rate (SAR) value. The SAR value obtained follows the secure limit. Finally, the antenna was fabricated, and the experimental results validated the simulation results.