Co-Circularly Polarized Planar Antenna With Highly Decoupled Ports for S-Band Full Duplex Applications

This work presents a unidirectional, co-circularly polarized (CP), printed antenna with highly decoupled or isolated transmit (T x ) and receive (R ports for 2.4 GHz in-band full duplex (IBFD) applications. The presented topology is based on four similar sequentially rotated trimmed patches right hand circular (RHCP) characteristics. symmetrical placement of two T respect to both R elements results in equal levels self interference (SI) which was suppressed through balanced excitation mode. mechanism effective suppression SI at each patch. residual further second feeding network deployed port proposed topology. employed networks provide superior performance ≤ 0.5 dB 6° magnitude phase imbalances respectively between the output over bandwidth interest. measured prototype achieve -10 better than 100 MHz ports. interport coupling validation model −70 across entire MHz. As per best authors’ knowledge, first one report such reduced whole impedance planar unidirectional radiation patterns co-RHCP characteristics modes overlapped bandwidth.