Design specification management with automated decision-making for reliable optimization of miniaturized microwave components

Funding Information: The authors would like to thank Dassault Systemes, France, for making CST Microwave Studio available. This work is partially supported by the Icelandic Centre for Research (RANNIS) Grant 217771 and National Science Centre of Poland Grant 2020/37/B/ST7/01448. Publisher Copyright: © 2022, The Author(s). © 2022. The Author(s).The employment of numerical optimization techniques for parameter tuning of microwave components has nowadays become a commonplace. In pursuit of reliability, it is most often carried out at the level of full-wave electromagnetic (EM) simulation models, incurring considerable computational expenses. In the case of miniaturized microstrip circuits, densely arranged layouts with strong cross-coupling effects make EM-driven tuning imperative to achieve the optimum performance. The process is even more challenging due to a typically large number of geometry parameters, and the lack of reasonable initial designs. The latter often encourages the use of global search procedures, which may be prohibitively expensive. In this paper, a novel automated framework for reliable optimization of miniaturized microwave components is proposed. Our methodology is based on design specification management, where the performance requirements imposed on the system are temporarily relaxed if the current design is unlikely to be improved (e.g., due to being away from the target operating frequency). The specifications are re-adjusted at each iteration of the algorithm, and eventually converge to their original values. Using two examples of compact microstrip couplers and a power divider, the presented technique is demonstrated to significantly improve the efficacy of local search routines under challenging design scenarios.Peer reviewe

Low temperature formation of low resistivity W contact with ultra thin mixed layer on molecular layer epitaxially-grown GaAs

Proceedings of the IEEE 24th international symposium on compound semiconductors, San diego, California, 8-11 Semptember 199

EM-Driven Multi-Objective Optimization of a Generic Monopole Antenna by Means of a Nested Trust-Region Algorithm

Publisher's version (útgefin grein)Antenna structures for modern applications are characterized by complex and unintuitive topologies that are difficult to develop when conventional, experience-driven techniques are of use.In this work, a method for the automatic generation of antenna geometries in a multi-objective set up has been proposed. The approach involves optimization of a generic spline-based radiator with an adjustable number of parameters using a nested, trust region-based algorithm. The latter iteratively increases the dimensionality of the radiator in order to gradually improve its performance. The method has been used to generate a set of nine antenna designs, representing a trade-off between minimization of reflection within 3.1 GHz to 10.6 GHz and a reduction of size. The properties of the optimized designs vary along the Pareto set from−10 dB to−20 dB and from 230 mm2to 757 mm2for the first and second objectives, respectively. The presented design approach has been validated against a genuine, population-based optimization routine. Furthermore, the smallest Pareto-optimal design has been compared to the antennas from the literature.This work was supported in part by the National Science Centre of Poland Grant 2017/27/B/ST7/00563 and by the National Centre for Research and Development Grant NOR/ POLNOR/HAPADS/0049/2019-00.Peer reviewe

SSB-Based Signal Processing for Passive Radar Using a 5G Network

This article presents an alternative processing chain for the passive radar using fifth-generation (5G) standard technology for broadband cellular networks as illuminators of opportunity. The proposition is to use a 5G synchronization signal block's (SSB) periodically transmitted modulated pulse in 5G-based passive coherent location (PCL) system processing. Although the SSB periodicity limits the velocity ambiguity, the article describes a solution to tackle this problem in a single target scenario. The method is advantageous when there is a lack of transmission in the telecommunication channel, and the 5G SSB is the only existing signal. The article proposes a signal processing pipeline for a 5G-based PCL that is inspired by passive radars using noncooperative pulse radar as an illumination source. The method has been validated using simulated and real-life 5G data measurements. The results presented in the article show the possibility of detecting a moving target with a lack of data transmission in the 5G network, using only the SSB when the classical passive radar signal processing fails. The presented results prove the possibility for a significant increase of 5G network-based PCL utilization in short-range applications