Effect of Wire Space and Weaving Pattern on Performance of Microstrip Antennas Integrated in the Three Dimensional Orthogonal Woven Composites

A conformal load-bearing antenna structure (CLAS) combines the antenna into a composite structure such that it can carry the designed load while functioning as an antenna. Novel microstrip antennas woven into the three dimensional orthogonal woven composite were proposed in our previous study. In order to determine the effect of the space between the conductive wires on the antenna performance, different space ratios of 1.7, 2.3 and 4.6 were considered in the design. Simulation results showed that when the space ratio increased, the frequency shift and return loss of the corresponding antenna became larger. And the antenna had relatively good performance when the space ratio reached 1.7. Two types of antennas were designed and fabricated with the ratio of 1.7 and 1 respectively and both of them obtained agreeable results. It was also demonstrated by the experimental that the orthogonal structure patch antenna had similar radiation pattern with the traditional copper foil microstrip antenna. However, the interlaced patch antenna had large back and side lobes in the radiation pattern because the existence of the curvature of copper wires in interlaced coupons lowered the reflective efficiency of the ground.