This paper presents a novel multiple splits octagon-shaped metamaterial which exhibits double left-handed frequency bands roughly from 9.25 GHz to 9.68 GHz and from 15.28 GHz to 15.36 GHz derived from the transmission characteristics by homogenization retrieval method. Two conventional microstrip patch antennas whose resonance frequency bands are located at the first left-handed frequency band and the second one respectively are designed to further investigate the influence by loading the proposed metamaterial as its superstrate. HFSS simulation numerical results indicate that the far field radiation directivity half-power bandwidth(HPBW) of the E-plane and H-plane have reduced by 64%, 63.7% and 59.4%, 59%, and the maximal gain increases from 8.251 dB to 11.024 dB and from 8.5432 dB to 11.9653 dB respectively after loading with the multiple splits octagonal metamaterial superstrate.

With two-dimensional device simulation software, the influence of the deep depletion (DD) of the silicon-on-insulator (SOI) lateral double-diffused metal-oxide-semiconductor (LDMOS) device substrate on the transient breakdown voltage (TrBV) was analyzed. Based on the changes in the characteristics of the charge distribution and the depletion layer in the device substrate with time and the related parameters in the off state, the mechanism of their action on the transverse and vertical breakdown voltages (BVs) was studied. TrBV demonstrates completely different characteristics from the static breakdown voltage (StBV) due to the DD effect of SOI LDMOSs. Low drift region concentration (Nd) and substrate doping concentration (Psub) are conducive to obtaining a high maximum TrBV. With increasing drain voltage (Vd), the turn-off nonbreakdown time (Tnonbv) of the device with higher Psub decreases faster. However, the Tnonbv with higher Psub is higher at low Vd. Therefore, the maximum Tnonbv can be obtained by optimizing Nd and Psub under a given Vd. In addition, Tnonbv is greatly reduced with increasing temperature.

In this paper, the transient breakdown voltage (TrBV) of a silicon-on-insulator (SOI) laterally diffused metal-oxide-semiconductor (LDMOS) device was increased by introducing a step P-type doping buried layer (SPBL) below the buried oxide (BOX). Device simulation software MEDICI 0.13.2 was used to investigate the electrical characteristics of the new devices. When the device was turned off, the SPBL could enhance the reduced surface field (RESURF) effect and modulate the lateral electric field in the drift region to ensure that the surface electric field was evenly distributed, thus increasing the lateral breakdown voltage (BV_lat). The enhancement of the RESURF effect while maintaining a high doping concentration in the drift region (N_d) in the SPBL SOI LDMOS resulted in a reduction in the substrate doping concentration (P_sub) and an expansion of the substrate depletion layer. Therefore, the SPBL both improved the vertical breakdown voltage (BV_ver) and suppressed an increase in the specific on-resistance (R_on,sp). The results of simulations showed a 14.46% higher TrBV and a 46.25% lower R_on,sp for the SPBL SOI LDMOS compared to those of the SOI LDMOS. As the SPBL optimized the vertical electric field at the drain, the turn-off non-breakdown time (T_nonbv) of the SPBL SOI LDMOS was 65.64% longer than that of the SOI LDMOS. The SPBL SOI LDMOS also demonstrated that TrBV was 10% higher, R_on,sp was 37.74% lower, and T_nonbv was 10% longer than those of the double RESURF SOI LDMOS.

In order to improve the efficiency and decision-making ability of airport operation support, the realization of estimation about service time of flight ground support can reduce the time and economic losses caused by flight delays. Considering the complexity and particularity of the service process, this article started from the analysis of the flight ground support process and constructed a mathematical model of the service time. The method of Principal Component Analysis (PCA) was used to reduce the correlation between variables, and a service time prediction model of flight ground support based on Deep Neural Network (DNN) was established. Finally, the flight support operation data of an airport were selected for simulation and verification. Experimental results show that the average absolute error of service time prediction can reach 2.709 min, the proposed model can effectively estimate the service time of flight support and has higher accuracy.

To improve the tradeoff between dynamic breakdown voltage (BV_dyn) and specific on-resistance (R_on,sp) in SOI LDMOS devices, a double-step-doped SOI LDMOS with a P-type buried layer (DSD-PBL SOI LDMOS) is proposed. The device incorporates a double-step-doped (DSD) drift region and a uniformly doped P-type buried layer (PBL) beneath the buried oxide (BOX). The DSD drift region and the PBL jointly modulate the electric-field distribution, enabling a high drift-region doping concentration while preserving the breakdown capability. Simulation results show that the proposed device achieves a BV_dyn of 678 V, which is comparable to the 680 V obtained by the step-doped SOI LDMOS (SD-SOI LDMOS) with the same DSD drift region and higher than the 605 V obtained by the conventional SOI LDMOS (C-SOI LDMOS). Meanwhile, the proposed device has a R_on,sp of 7.84 Ω⋅mm², corresponding to reductions of 39.0% and 45.6% compared with the SD-SOI LDMOS and C-SOI LDMOS devices, respectively. Under identical switching and thermal-management conditions, the reduced R_on,sp results in lower conduction losses and improved thermal performance.