Efficiency-Enhanced and Size-Reduced Coupled Twin Slots Capacitively Fed by Conductor-Backed Coplanar Waveguide

An efficiency-enhanced and size-reduced coupled twin-slot antenna capacitively fed by a conductor-backed coplanar waveguide (CBCPW) is proposed. The efficiency enhancement is achieved by using a capacitive feed with a T-match stub to replace the inductive feed such that the lengths of the twin slots can be optimized for highest antenna efficiency, and the impedance matching can be accomplished by adjusting the parameters of the T-match stub. Consequently, the size of the antenna is also reduced. The proposed design is simulated, fabricated, and tested, showing high antenna efficiency of 80.8% at 5.05 GHz with an FR4 substrate used.