Dual-Polarized Filtering Magnetoelectric Dipole Antenna Arrays with High Radiation-Suppression Index for 5G New Radio n258 Operations

In this communication, a dual-polarized filtering magneto-electric dipole (FMED) antenna and arrays are proposed for 5G n258 (24.25-27.5 GHz) operations. The FMED antenna was devised to incorporate filtering mechanisms using a built-in substrate integrated waveguide (SIW) based filter plus slot-and-notch etching on the dipole element. As such, lower and upper radiation cutoffs and nulls were produced and tuned, independently. To overcome the problem of “high selectivity” of a filtering antenna that has not been correctly quantified and thus has no comparison, a new skirt measure metric named as radiation suppression index is initiated here. Design steps of the FMED element and novel feeding techniques are elaborated, where the SIW-based series-parallel slot-coupled feeders and the slot-coupled differential power divider were conceived for large-size array, to combat with the insertion losses. A prototype of the 4×4 FMED array was implemented and tested for experimental verification. A high gain of 16.8±1.4 dBi with a 3-dB gain bandwidth of 24-27.7 GHz and a radiation efficiency of 78% were accomplished.