Broadband Split Ring Resonator-Based Antennas at 140 GHz in Embedded Wafer Level Ball Grid Array Technology

Two single-ended split ring resonator-based antennas are demonstrated in standard embedded wafer level ball grid array (eWLB) packaging technology - a two-element, capacitively-fed, square split ring resonator (SSRR) antenna array and a round SRR antenna (RSRR). The RSRR has a peak gain of 6.4 dBi and a relative bandwidth of 20.8%; the capacitively-fed SSRR array has a peak gain of 6.9 dBi and relative bandwidth of 28.6%. The array has one of the widest bandwidths of millimeter-wave arrays, 60 GHz and above, realized in eWLB packaging. All the antennas have a ground plane reflector realized on a Rogers 4003C substrate. Measured and simulated return loss, gain and radiation pattern results agree well for both the RSRR antenna and the SSRR array.