This study investigates the size-dependent wave propagation behaviors under the thermoelectric loads of porous functionally graded piezoelectric (FGP) nanoplates deposited in a viscoelastic foundation. It is assumed that (i) the material parameters of the nanoplates obey a power-law variation in thickness and (ii) the uniform porosity exists in the nanoplates. The combined effects of viscoelasticity and shear deformation are considered by using the Kelvin-Voigt viscoelastic model and the refined higher-order shear deformation theory. The scale effects of the nanoplates are captured by employing nonlocal strain gradient theory (NSGT). The motion equations are calculated in accordance with Hamilton’s principle. Finally, the dispersion characteristics of the nanoplates are numerically determined by using a harmonic solution. The results indicate that the nonlocal parameters (NLPs) and length scale parameters (LSPs) have exactly the opposite effects on the wave frequency. In addition, it is found that the effect of porosity volume fractions (PVFs) on the wave frequency depends on the gradient indices and damping coefficients. When these two values are small, the wave frequency increases with the volume fraction. By contrast, at larger gradient index and damping coefficient values, the wave frequency decreases as the volume fraction increases.

ABSIlRACT A novel method for characterizing the surface resistance of two conducting plates shorted at both ends of a dielectric resonator is given in this paper. It utilizes only one dielectric resonator that can resonate with both TE,, and TE921 mode at same frequency. Thlhe theoretical relat'ions and experimental results are also given. The described method has been provedto be convenient, relatively accurate, and of practical usefulness.

Using different diameters of conducting plates to tune the resonate frequency of cylindrical or ring dielectric resonator (DR) antennas is presented in this paper. This technique has following two advantages for the DR antenna design. The first it provides a very easy way tuning a DR antenna to operate at the design frequency without changing antenna performance. The second it can be used to reduce the DR antenna size, because the maximum frequency tuning range can reach about 300 to 500 MHz lower than original design frequency.

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