A cpw fed double slot antenna can provide narrower beamwidth than a signle slot. Usually slot antenna are not designed for wide bandwidth. For wide bandwidth, spiral antenna or log periodic antenna are better choices.
Dear THz, I am designing a two arm Archmedian spiral antenna. I am not getting good s11 results. My freq range is 2-18GHz. How do you think I can enhance its bandwidth and improve s11.
Thanks