Conditioning of a metal surface in a high-voltage system is the progressive development of resistance to vacuum arcing over the operational life of the system. This is relevant for accelerator cavities, where high level of performance is only achievable after a long conditioning period. Beyond the accelerator research field, this is an important topic for any technology where breakdowns can cause device failure, either by directly disrupting device operation or by causing cumulative hardware damage.

We are developing a direct method to measure the surface resistivity of a metal surface that is being conditioned with a HV DC system by inducing a high frequency (GHz) radio-frequency current in the parallel-plate electrode system. If the system can function as a resonant cavity, the surface resistivity data would be encoded in its quality factor (Q-factor). The changes in the resistivity measured in cryogenic conditions would indicate a formation of dislocations under the surface, something that has been speculated as an important process behind the conditioning.

In this paper, we present two modified designs of the electrode system, which will act as a resonant cavity, the results of 3D EM simulations and experimental results regarding the characterization of this resonant system.

In this paper, the design theory of an 8 GHz oscillator with a new structure of active dielectric resonator (DR) is presented. The new structure emphasizes on phase noise reduction by using only one active device. The proposed structure uses additional feedback from transistor to resonator in order to increase the quality factor. Measurement results report that phase noise is reduced to −145.19 dBc/Hz at 100 kHz offset frequency which represents 12 dB improvement compared with oscillators with passive DR. Also, in comparison with conventional active resonator oscillators, noise source of the second amplifier which makes spurious oscillation is removed. The size and power consumption are reduced due to the use of a single transistor. This structure has the lowest phase noise in comparison with other DR oscillators. In order to implement the proposed oscillator, a circuit including amplifier, resonator, coupler, and phase shifter is designed and realized.

A simple closed-form analytical formula is proposed to compute the probe reactance of an equilateral triangular patch antenna. The variation of the probe reactance with the variation of antenna dimension, substrate electrical parameters, and probe location is examined thoroughly. The computed values employing the present model show excellent agreement with experimental and simulation results.

In this paper, the deflection, natural frequency and damping quality factor of a viscoelastic microplate under an electrostatic actuation are investigated. The microplate is assumed as a CNT-reinforced nanocomposite microplate, and an electrostatic actuation is applied on it. The nonlinear equations of motion are derived using the Von-Karman plate theory, and the Kelvin-Voigt viscoelastic model. In order to obtain the material properties of the nanocomposite microplate, the Eshelby–Mori–Tanaka method is implemented. The static pull-in instability of the microplate is obtained. It is shown that the nanocomposite microplate can both increase the deflection and natural frequency of the micro devices. So, one may have a nanocomposite microplate with the same deflection of the SiO2 microplate, while its frequency would be 1.45 times of the SiO2 microplate. This characteristic is highly desirable in microswitches. Also, it is shown that the damping quality factor of the nanocomposite microplate is much greater than SiO2 microplate. This fact limits the implementation of a nanocomposite microplate as a vibrating element of the micro devises. So, there are great beneficial static and frequency response characteristics for nanocomposite microplates. But, it is not recommended for microresonators due to high damping characteristics.