OAM antenna arrays at E-band

This paper introduces antenna arrays to generate mode 1 and mode 3 orbital angular momentum (OAM) radio beams at 73.5 GHz (E-band) using half wavelength dipoles. Design details are presented with the arrays fabricated on 0.127 mm-thick high performance FR408 substrate with relative permittivity of 3.75 and loss tangent of 0.018. ANSYS HFSS and AWR AXIEM simulations have been used to optimize the array designs and feeding networks. Measured results include |S11| (dB) across E-band and far-field radiation patterns at 73.5 GHz. The simulations and measurements are in good agreement and demonstrate how uniform circular arrays for E-band communications can be implemented in a simple manufacturing process with flexible substrates.