The invention discloses a frequency-reconfigurable
microstrip patch yagi antenna, which comprises a three-layer structure. The first layer of the three-layer structure comprises a first
dielectric substrate. A
coupling microstrip line, a
direct current bias circuit and a
metal through hole are arranged on the upper surface of the first
dielectric substrate. An impedance conversion line, a reflection patch, an active patch and a director patch are arranged on the lower surface of the first
dielectric substrate. The
reconstruction method of the yagi antenna is as follows: a direct-
current voltage is added across the two ends of the
liquid crystal material, and the direct-
current voltage is loaded on a medium below the active patch through the
metal through hole via a T-shaped bias device. Inthis way, the effective dielectric constant of the
liquid crystal material can be changed by changing the
voltage of the
direct current bias circuit, and then the working frequency of the yagi antenna is changed. According to the scheme, the antenna and the method are adopted, and the frequency reconstruction of the antenna is convenient. The reconstructed antenna is easy to integrate, and the
processing difficulty of the antenna is reduced. Meanwhile, a
main lobe beam can be concentrated between the side shooting direction and the end shooting direction, and the
signal receiving effect is better.