Conformal Antenna with Reconfigurability of Monopole-like and Broadside Patterns Realized with Polymer-Conductive Textile Composite

A conformal antenna with a capability of electronically switching between monopole-like and broadside radiation modes is presented. The design is based on a proximity-fed circular patch, loaded with a ring patch and four rectangular slots. The reconfigurability is achieved through activation and deactivation of the slots using PIN diodes, to switch between TM02 (monopole-like) mode and perturbed TM02 (broadside) mode. Polymer-conductive textile composite material is used to implement the antenna, with all antenna elements including DC biasing circuit and associated electronic components fully integrated inside the polymer. This configuration makes the antenna robust against deformation and harsh environment. Experimental investigations on the antenna RF performance including bending tests are presented. The measurements demonstrated that under bending, the antenna retained its reconfigurability with stable impedance and radiation performance relative to those of the flat case, i.e., 17.9% overlapping bandwidth of the two radiation modes and peak realized gains of 1.75 and 2.9 dBi at 5.2 GHz in monopole-like and broaside modes, respectively.