Millimeter-wave Wideband Filtenna for Phased Array Beam Scanning Applications

This paper presents a wideband filtenna and phased array for millimeter-wave applications. The proposed filtenna element composed of a $2 \times 2$ patch array loaded with complimentary split resonant rings (CSRR) and fed by an end-shorted microstrip through a slot on the ground plane. Two radiation nulls at the lower and higher band edges are introduced owing to the feeding structure and the CSRRs is adopted to further increase the suppression level at the high band. The $\mathbf{- 1 0} \text{dB}$ impedance bandwidth of the proposed filtenna element can cover $25-42 \text{GHz}(50.7 \%$) with a maximum realized gain of $\mathbf{6 . 4} \mathbf{d B i}$. The antenna elements are further developed to a $1 \times 8$ array to verify the phased array performance. The simulation results indicate the designed array has a stable impedance matching and a wide beam scanning ability.