Compact wdeband millimeter-wave substrate integrated waveguide fed interdigital cavity antenna array

In this paper, a compact wideband millimeter-wave substrate integrated waveguide (SIW) interdigital cavity antenna based on a novel coplanar waveguide (CPW) fed power divider is presented. First, through combining the CPW-slotline transition and the slotline-SIW transition, a two-way power divider with S₁₁ <;-15dB from 34.6 GHz to 37.1 GHz and good balance performance is designed. Then, the substrate integrated cavities (SIC) are placed interdigitally based on the power divider, which makes the antenna array structure much compact. In the end, this antenna array is fabricated and measured. The results show that the proposed antenna yields an impedance bandwidth of 33.3-38 GHz (13.1 %). The compact wideband millimeter-wave SIW interdigital cavity antenna indicates a wide application foreground as its distinguish compact-size feature especially when the cavity number is relatively big.