Abstract : the propagation phase constant (?) of the current flowing through the antenna element. The material is classified as natural if the value of ? is greater than zero (?>0) other than The material is classified as MTM if the value of ? is less than zero (? < 0) for a specific wave frequency band or zero at the non-zero frequency (?=0).[36] The right-handed (RH) material having ? > 0 and ? > 0 demonstrates the phase constant of wave propagation (?) to be a positive value (? > 0) and is termed as double-positive (DPS) material
