Multi-band and broadband coaxial CTS array design

We present a new multi-band phased array design based on the coaxial continuous transverse stub (CTS) technology. This design is a departure from previous CTS approaches, which were pursued using planar structures. Coaxial CTS antennas of one-, two-, three, and six-element arrays were simulated using FDTD and the method of moments-based IE3D/sup (R)/ commercial software. A low-frequency coaxial CTS array was designed at 4 GHz, and simulation results showed S/sub 11/ = -12 dB and 48% radiated power. The other three-element array was designed at 32 GHz and, when combined with the low- frequency array, S/sub 11/ < -8 dB and the radiated power at 32 GHz was over 80%. Coaxial CTS antenna arrays and their new potential multi-band operation thus provide valuable low-cost alternatives for base station antennas and a variety of military applications.