Liquid crystal-based microstrip patch antenna for widening frequency tuning range and miniaturizing radiating unit

A microstrip patch antenna based on liquid crystal, comprising:

• a first substrate including a second radiating unit provided in a patch type, and a second bias line to receive power from a power supply such that a voltage is applied to the second radiating unit;
• a second substrate disposed under the first substrate, and including a liquid crystal cavity for injecting liquid crystal;
• a third substrate disposed under the second substrate, and including a first radiating unit provided in the patch type and a first DC bias line to receive the power from the power supply such that a voltage is applied to the first radiating unit;
• and
• a fourth substrate disposed under the third substrate, and including a feeding unit and the ground surface and having a feeding structure to transmit a signal from the feeding unit to the first radiating unit.