Ultra-Low-Loss Millimeter Wave Beam Scanning Antenna Using Piezoeletric Actuation

An enhanced beam scanning angle, leaky-wave, antenna is presented with high efficiencies at millimeter wave frequencies and above, enabled by the tuning mechanism residing wholly outside the millimeter wave circuit. This is achieved by forming a cavity between a Partially Reflective Surface (PRS) and a phase tuneable High Impedance Surface (HIS). A phase change is achieved by the micro-motion of the HIS ground plane, provided by a piezoelectric actuator. This phase change translates to a beam steer of the leaky wave radiating from the PRS. In order to compensate for limited beam scan, a dual cavity has been incorporated into a single antenna, in which resides a switchable feed that can selectively energize parts of the cavity to create a ±40° beam steer with radiation losses of 0.65-0.92 dB, total losses ranging between 1.6-2.58 dB, realized gain between 17.8 and 20.63 dBi, and bandwidth of 2 GHz.