K/Ka-Band Full-Duplex Satcom ESA Using a Varactor-Based Metasurface Aperture

We present a shared aperture electronically scanned array (ESA) with full duplex capability. The antenna covers the full K/Ka commercial and military receive (17.7-21.2 GHz) and transmit (27.5-31 GHz) bands for satellite communications (Satcom). The antenna is based on the concept of holographic beam forming and is implemented using diffractive metasurfaces and varactor diode tuning. The metasurface was manufactured using processes commercialized for mini-LED displays and was experimentally characterized. With an 82cm radial radiative aperture, the antenna achieves a maximum gain of 40.4 dBi at receive and 40.7 dBi at transmit bands in full duplex mode. Electronic control over polarization and a wide beam scanning from 15
^o
to 90
^o
in elevation and 360
^o
in azimuth were also experimentally demonstrated, with a scan loss near to theoretical limits at the receive band.