Fourier-transform spectroscopy of NNO in the 3800-9000 cm region and global modeling of its absorption spectrum

The absorption spectrum of ¹⁴N¹⁵N¹⁶O-enriched sample of nitrous oxide has been recorded at Doppler limited resolution with a Fourier-transform spectrometer in the spectral range 3500-9000 cm⁻¹. More than 12 000 transitions of ¹⁴N¹⁵N¹⁶O were observed and ro-vibrationally assigned on the basis of the global effective Hamiltonian model. The band-by-band analysis led to the determination of the ro-vibrational parameters of a total of 107 bands. Among the 107 bands, 80 are newly observed, for 27 others the rotational analysis is significantly extended and improved. The effective Hamiltonian parameters are determined from global fitting to the observed line positions presented in this paper and collected from the literature. As a result, a set of 117 obtained effective Hamiltonian parameters reproduces 16 134 observed line positions of 148 bands with RMS of 0.0014 cm⁻¹.     

Theoretical line list of D2 O up to 16,000 cm with an accuracy close to experimental

A line list for D₂ ¹⁶O isotopologue of water molecule was calculated in the region 0-16,000 cm⁻¹ with energy levels up to J=30. Variational calculations are based on the semi-theoretical potential energy surface obtained by morphing ab initio potential using the experimental energy levels of D₂ ¹⁶O. For energy levels with J=0, 2, 5 and 10, the standard deviation of the fit is 0.023 cm⁻¹. This line list should make an excellent starting point for spectroscopic modeling and analysis of D₂O rovibrational spectra.     

A Method for Determining the Dielectric Constant of Microwave PCB Substrates

This paper presents a simple method for determining the dielectric constant of microwave PCB substrates. In the presented method, a bandpass microstrip filter designed on the PCB substrate with a user-predicted dielectric constant value is implemented for a given center frequency. The simulation results of the designed bandpass filter are obtained by the help of microwave design software; XFDTD?. Experimental results regarding the filter frequency characteristic are accomplished by means of a vector network analyzer. The simulation results of the designed filter are modified to overlap with the experimental ones by varying the dielectric constant value. When the simulation and experimental results are overlapped, the value of dielectric constant is accurately selected. In order to illustrate the validity of proposed method, the dielectric constant values of flame resistant-4 (FR4) substrates are acquired at IEEE 802.11b/g and IEEE 802.11a wireless local area network (WLAN) application frequencies. The results obtained by using the presented method agree with the previous studies in the literature.     

全无源有保护的O-band CWDM型5G前传创新方案

此文提出的创新型低成本前传设备产品主要基于三大核心关键技术：（1）采用O-Band高速彩光光模块；（2）采用全无源低成本的WDM双星形架构；（3）远端无源，仅在局端增加有源保护板的WDM的OLP保护新机制。该创新型产品使用的O-Band无源彩光CWDM技术简单、便于野外部署和管理维护，大大降低了网络建设的综合成本，其新型OLP保护管理能力也满足了5G前传网的高可靠性要求。     

DSA guiding template assignment with multiple redundant via and dummy via insertion

As an emerging manufacture technology, block copolymer directed self-assembly (DSA) is promising for via layer fabrication. Meanwhile, redundant via insertion is considered as an essential step for yield improvement. For better reliability and manufacturability, in this paper, we first concurrently consider DSA guiding template cost assignment with multiple redundant via and dummy via insertion. Firstly, by analyzing the structure property of guiding templates, we propose a building-block based solution expression to discard redundant solutions. Then, honoring the compact solution expression, we construct a conflict graph with dummy via insertion, and then formulate the problem to an integer linear programming (ILP). In addition, to optimize the guiding template cost, we incorporate it into the objective of ILP by introducing vertex weight and edge weight in conflict graph. To make a good trade-off between solution quality and runtime, we relax the ILP to an unconstrained nonlinear programming (UNP). Finally, a line search optimization algorithm is proposed to solve the UNP. Experimental results verify the effectiveness of our new solution expression and the efficiency of our proposed algorithm. Specifically, our guiding template cost optimization method can save 18% total guiding template cost.     

Compact microstrip low pass filter with flat group-delay using triangle-shaped resonators

In this paper, a compact microstrip lowpass filter (LPF) using triangle-shaped resonators is presented. The designed LPF includes three symmetric triangle-shaped resonators to provide a suitable passband and sharp response. A suppressing unit composed of several suppressing cells is designed to obtain a wide rejection band and low insertion loss in the passband. The fabricated LPF has been measured and indicts that it has −3 dB cut off frequency at 5.15 GHz. The rejection band has been expended from 5.51 GHz to 43.2 GHz with maximally flat return loss in this region nearby to 0 dB. Also, simulation and experimental results show that the proposed filter has a very flat group delay in the passband, which is the minimum value in comparison with the published works since 2017.