Ka-Band CTS Antenna Based on Suspended Stripline Feeding Network

In this work, we present a Ka-band flat antenna based on continuous transverse stub (CTS) technology and suspended stripline (SSL) feeding network. The proposed flat antenna consists of a CTS radiation structure, a parallel plate waveguide to suspended stripline (PPW-SSL) transition structure, and suspended stripline unequal power division networks, which exhibits wide bandwidth, high efficiency, and low sidelobes. The measured results show that the reflection coefficient better than -13.5 dB, the aperture efficiency higher than 56% are achieved over the frequency range of $18.0-31.0 \mathrm{GHz}$.