Extremely Low-Profile Monopolar Microstrip Antenna with Wide Bandwidth

In this paper, we propose a new monopolar microstrip antenna for a high-speed moving swarm sensor network. The proposed antenna shows an extremely thin substrate thickness supported with an omni-directional radiation pattern and wide operation frequency bandwidth. First, to achieve the low-profile monopolar microstrip antenna, the symmetrical center feeding network and the gap-coupled six arrayed patches which form a hexagonal microstrip radiator were utilized. The partially loaded ground-slots under the top patches were employed to improve the radiation performance and adjust the impedance bandwidth. Second, to obtain the broad bandwidth of the low-profile monopolar microstrip antenna, the degenerated non-fundamental TM02 modes, that is, even and odd TM02 modes, were carefully analyzed. To verify the feasibility of the degenerated TM02 mode operation, the parametric study of the proposed antenna was theoretically investigated and implemented with the optimized parameter dimensions. Finally, the fabricated antenna showed a 0.254 mm-thick substrate and demonstrates 1.5-wavelength resonant monopolar radiation with broad impedance bandwidth of 855 MHz and its factional bandwidth of 15.24% at the resonant frequency of 5.57 GHz.

The study of a half-spin relativistic particle in the rotating cosmic string space–time

In this paper, a charged half-spin particle depicted by the Dirac equation in the presence of a uniform magnetic field and a mixed potential are analyzed in the rotating cosmic string space–time. In order to facilitate this study, we assume that the symmetrical center of the potential is on the string and the magnetic field is parallel to the string. Based on the functional analysis method, we obtain the energy eigenvalues for different physical situations. It shows that the energy levels of the system depend explicitly on the angular deficit [Formula: see text] and the rotational parameter [Formula: see text] which characterize the global structure of the metric in the space–time of the rotating cosmic string.

Simulation Study of the Array Antenna

In this paper, after introducing the concept of far zone field, expression of the electric and magnetic field intensities of symmetrical center-fed dipole is derived based on structure of the array antenna by the electric field intensity formula of symmetrical center-fed dipole. When the electric field intensity of the array antenna is known, the direction function of the array antenna is obtained by concept of the primary pattern and array pattern , Finally, computer programming simulation is used to realize the visualization of the direction function of the primary pattern and array pattern. . In this way, the accurate data and precise curve are obtained so the goal of direct-viewing analysis of the problems is achieved.

Relation between Residual Stresses in TBCs Interface Area with TGO Interface Morphology

Considering the thermally-growth oxide (TGO) that grows between top ceramic coating (TCC)and bond coat (BC) interface and surface morphology of bond coat in a TBC system, the effect of residual stresses distribution by actual and assuming interface morphology in TGO area was calculated with ABAQUS. The calculating result shows that the residual stress of TCC/TGO and TGO/TCC interface are affected by interface morphology obviously, σyy is tensile at peaks and compressive at valleys for both with maximum stress beside the symmetrical center and at the symmetrical center respectively. σyy stress in TCC is bigger than that of BC for both. σxx stress of actual TGO in the three layers remains the same, the interim area change dramatically with TCC layer compressive stress, TGO layer smaller compressive stress, BC layer tensile stress.