This article presents a novel filter-based analysis for conventional rectangular patch antenna (RPA) using Composite Right/Left-Handed Transmission Line (CRLT-TL) theory. We introduced two circuit models for RPA, described by lumped components and transmission line (TL) elements. An RPA is considered a Symmetric CRLH (S-CRLH) unit-cell. We validated the analysis by comparing the circuit model and full-wave analysis simulation results. The TL circuit model error from the full-wave analysis is less than 5%. A dual-band Zeroth-Order Resonant (ZOR) antenna is designed and manufactured based on the introduced Lumped element circuit model. We obtain the antenna circuit model by incorporating the RPA lump circuit model with LC resonators. We implement the antenna structure by combining RPA and complementary split ring resonators (CSRR), which are modelable by LC resonators. We initialized antenna center frequency bands for WiMAX 2.45 GHz and 3.60 GHz. The initializing center frequencies feature is controllable by CSRRs. The simulation and measured results are in good agreement. The proposed antenna dimensions are 43.22×43.22×0.81 mm³. The measured gains are 3.47 dB and 4.64 dB for 2.45 GHz and 3.60 GHz, respectively. Also, the fractional bandwidth is 4.03% and 1.39%, respectively. The radiation pattern is nearly omnidirectional; the simulated efficiency is 90% for 2.45 GHz and 87% for 3.60 GHz frequency bands.