We propose a novel metamaterial antenna that is based on loading a single complementary split ring resonator (CSRR) onto a substrate integrated waveguide (SIW) structure. Negative order and zeroth-order resonance can be observed in the proposed structure. These resonance modes are used to reduce the antenna size. In addition, a high quality (Q) factor of the CSRR-loaded SIW structure can minimize the radiation loss. The -1st, 0th, and 1st resonances are experimentally observed at 6.63, 13.68, and 20.31GHz with maximum gains of 1.59, 3.97, 6.83dBi, respectively. The electrical size of the antenna at the -1st resonance is only 42% of the resonance of a square microstrip patch antenna.