An ultra-compact antenna for low frequency application is presented. The resonant frequency band of the proposed antenna is centered at 403.5 MHz, employed for medical implant communication service (MICS) band. The proposed antenna is designed and fabricated on a substrate with ε r = 4.4, tan δ = 0.02, and thickness h = 1.6 mm. The size of the antenna is only 29 mm × 16.5 mm × 1.6 mm, making it very compact for low frequency of operation. The antenna is evolved from a CPW transmission line. During the process of evolution of the proposed antenna, dual-composite right left handed (D-CRLH) behavior is confirmed from the dispersion diagram. The equivalent lumped circuit model for the antenna is also developed, and the D-CRLH behavior is also confirmed from the circuit model.