Abstract: A low-frequency heating apparatus is provided. The low-frequency heating apparatus includes a signal generator configured to generate an operation frequency for inducing a current through a coil unit surrounding an internal area of a housing of the heating apparatus, a power amplifier configured to amplify power of the operation frequency to a predetermined level and transmit the amplified operation frequency to the coil unit, the coil unit configured to be energized to heat an object provided inside the housing through a magnetic field generated by the current, and at least one processor configured to monitor an impedance value of the coil unit resonating at the operation frequency and control a resonant operation of the coil unit based on the impedance value of the coil unit and an impedance value of the power amplifier.

Abstract: An antenna device is provided. The antenna device may include a conductive radiator pattern formed on one surface of a dielectric substrate, an artificial magnetic conductor layer including at least one unit cell formed on the other surface of the dielectric substrate, and a shorting pin connected to the unit cell. The artificial magnetic conductor layer may be configured to form an induction current of the same phase with regard to a signal current flowing through the conductive radiator pattern.

Abstract: A low-frequency heating apparatus is provided. The low-frequency heating apparatus includes a signal generator configured to generate an operation frequency for inducing a current through a coil unit surrounding an internal area of a housing of the heating apparatus, a power amplifier configured to amplify power of the operation frequency to a predetermined level and transmit the amplified operation frequency to the coil unit, the coil unit configured to be energized to heat an object provided inside the housing through a magnetic field generated by the current, and at least one processor configured to monitor an impedance value of the coil unit resonating at the operation frequency and control a resonant operation of the coil unit based on the impedance value of the coil unit and an impedance value of the power amplifier.

Abstract: An antenna device is provided. The antenna device may include a conductive radiator pattern formed on one surface of a dielectric substrate, an artificial magnetic conductor layer including at least one unit cell formed on the other surface of the dielectric substrate, and a shorting pin connected to the unit cell. The artificial magnetic conductor layer may be configured to form an induction current of the same phase with regard to a signal current flowing through the conductive radiator pattern.