Leaky Characteristics of the First Higher Order Mode in Microstrip Line with DNG/DPS Substrates

The leaky characteristics for the first higher order mode in microstrip line with double negative (DNG) and double positive (DPS) dielectric substrates are carefully investigated. Our emphasis is laid on the variations of the leaky characteristics of the antenna with frequency. The numerical results show that the frequency variations of negative permittivity and permeability greatly influence the leaky characteristics of the antenna in antenna-mode region. It gives an important guideline and consideration in the design for the new type of microstrip line leaky-wave antenna.