Exploratory Study of MM-wave Patch Antennas for Strain Measurement and Crack Detection.

摘要

The feasibility of applying patch antennas for strain measurement was investigated. The relationship between the antenna resonant frequency and strains applied along the electrical length and width direction of a patch antenna was derived analytically, based on transmission line mode. A dual- frequency patch antenna was designed and fabricated using conventional photolithography techniques. The application of the patch antenna for strain measurement was evaluated by bonding the patch antenna to an aluminum cantilever beam and applying loads at the free end of the cantilever beam. The shifts of the return loss S(sub 11) curves under loads were correlated to the strains experienced by the patch antenna. The strain sensitivity of the antenna obtained from experimental measurements agreed well with the analytical prediction. Research issues associated with interrogating the antenna resonant frequency using a monostatic radar system is also discussed.