Polarization-changeable phased array

If a phased array is to radiate both left-hand circular polarized beam and right-hand circular polarized beam, it must switch the circular-polarization ports of each antenna element by using switching devices. Here the author explains how a polarization-changeable phased array without active devices such as switching devices can be designed. This phased array can also be applied to establish arbitrary ellipticity and arbitrary tilt angle of polarization. It can also be applied to polarization-adaptive phased array.