Pattern Reconfigurable Yagi Antenna Based on Active Corrugated Stripline

We present a method of designing pattern reconfigurable Yagi antenna based on the active corrugated strip line (ACSL) technology. A conventional dipole is used as a driven element, and a pair of ACSLs in different states is set on both sides of the dipole symmetrically. The ACSLs in different states have different average phase constants (
$\beta _{\mathrm {ave}}$
), where the ACSL with a lower
$\beta _{\mathrm {ave}}$
serves as a director, while the other serves as a reflector. By changing the
$\beta _{\mathrm {ave}}$
of the ACSLs, a front-to-back pattern reconfigurable Yagi antenna is realized. A prototype of the proposed antenna working at the center frequency of 2.4 GHz was fabricated and measured to validate the predicted performance. The fabricated antenna has a compact size (
$0.42\lambda _{0}\times 0.42\lambda _{0}$
,
$\lambda _{0}$
is the wavelength in space) and low profile (
$0.004\lambda _{0}$
). The measured −10 dB impedance bandwidth and the gain of the antenna are 8.3% and 6.2 dBi (at 2.4 GHz), respectively.