Wideband Magnetoelectric Dipole Phased Array With SICL Feed and Reactive Impedance Surface

A compact wideband magnetoelectric (ME) dipole antenna array with substrate-integrated coaxial line (SICL) feed is proposed for wide beam steering (BS) applications. The SICL line is transformed into a grounded coplanar waveguide (GCPW) to feed the ME dipole element. The element is first miniaturized using a closed U-shaped slot realized on SICL-GCPW ground, C-shaped shorting strip on ME dipole, and reactive impedance surface (RIS) loading. The element achieves an impedance bandwidth (IBW) of 59.44% at the center frequency ( $\rm f_{0}$ ) of 22.125 GHz while maintaining a compact size of $\rm 0.33 \lambda _{0}\, \times \, \rm 0.28 \lambda _{0}$ (excluding RIS), where $\rm \lambda _{0}$ is free space wavelength at $\rm f_{0}$ . A corporate feed network with low port imbalances is designed using SICL technology, which is used to realize an eight-element uniform linear array (ULA). Experiments reveal a measured IBW of 55.43% and a measured peak realized gain of 13.2 dBi ( $11.53~\rm \pm ~1.67$ dBi). BS measurements at 24 and 27 GHz show realized gain BS to $\rm \pm 45^{\circ } $ with worst case total scan loss (TSL)/sidelobe level (SLL)/cross-polarization discrimination of 3/-10.9/15.2 dB and 4.13/-5.2/14.8 dB, respectively. Array prototypes use Rogers 4003 with width $3.96\lambda _{0}$ ( $\rm f_{0} =22.15$ GHz).