Electromagnetic devices for next-generation wireless communication systems

In this paper, we present two microwave devices at 1 GHz for next-generation wireless communication systems. The first device is a magnet-less circulator that consists of three resonant branches connected in a delta topology and spatio-temporally modulated with 120 deg phase difference between each other. The proposed circulator is fully compatible with standard CMOS technologies and holds the promise to enable full-duplex wireless. The second device is an active microwave cloak that can mitigate the self-interference problem in massive MIMO systems. The presented cloak can achieve 10 dB scattering reduction over a 20% fractional BW, thus making it suitable for practical systems with digital or analog modulation schemes.