A low profile single feed compact dual-band penta-polarization agile microstrip antenna for interference mitigation in point to point link in Ultra-Dense environment

This study takes an antenna perspective approach to mitigate signal interference issues in ultra-dense environment along with communication and signal processing domain. A compact single layered dual-band penta-polarization agile microstrip patch antenna (MSA) using single feed is studied and proposed. Each band switches between five distinct polarization states. Additionally, the proposed antenna possesses a very low profile of less than 0.01λ (λ free-space wavelength). A square patch is enclosed by a square ring to attain two distinct reconfigurable frequency bands by using switching diodes and biasing networks. Orthogonal microstrip lines connected with a single coax feed are selectively chosen by biasing network to excite the adjacent patch edges to achieve dual linear polarization (LP). Circular polarization (CP) with dual sense of rotation at each band is attained by switchable diagonal-truncated corners of outer ring. Subsequently, 45° slant polarization is achieved by simultaneous activation of the orthogonal feed lines with equal phases and amplitude. A penta-polarized antenna prototype is designed and fabricated to operate at 5.2 GHz and 5.8 GHz bands respectively. Simulation results of all ten reconfigurable states are found to be consistent with the measurement.