Resonant circular patch microstrip antenna with air gap
The resonant frequency and bandwidth characteristics of superstrate loaded air gap tuned circular patch microstrip antenna are investigated for different structural parameters. The problem is formulated in spectral domain and Galerkin's method is used for the solution. It is shown that adjustable air gap between the ground plane and substrate compensates superstrate loading effect on the resonant frequency, increases bandwidth and provides tunable operational characteristics.
Analysis of circular microstrip antennas with superstrate
The spectral domain analysis is applied to study the effects of dielectric cover on a circular microstrip patch antenna. Numerical examples indicate that the resonant frequency of the patch is decreased considerably while the bandwidth is varied slightly.
Thermal-mechanical fully coupled analysis of high-speed angular contact ball bearings
The thermal and mechanical properties of angular contact ball bearings are critical to their operating accuracy and service life. On the basis of the theory of dynamics and frictional heat generation, this work establishes a thermal-mechanical fully coupled model. The high-speed motion characteristics, temperature, and dynamic stiffness are analyzed, and the simulation results are compared with the theoretical calculation and experimental results. Then, the temperature and axial deformation of the bearings under different rotation speeds are analyzed, and the laws of mechanical and thermal characteristics of the bearings are obtained. Results show that an increase in the rotation speed of the inner ring causes the temperature of each component to increase, with the contact area of the balls showing the greatest increase in temperature. An increase in rotation speed also increases the axial deformation of the inner ring.