{"title":"Bandpass Filters with Increased to 3N+1 Number of Attenuation Poles","authors":"Sergii Litvintsev, Alexander Zakharov","doi":"10.3103/s073527272311002x","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>N-order bandpass filter (BPF) with parallel resonators and cross and mixed couplings can have (<i>N</i> + 1) transmission zeros (TZ) located on the complex plane <i>s</i> = σ + jω. TZs at real frequencies (jω axis) are also called attenuation poles (AP). The authors propose an alternative possibility of AP forming in filters using resonators with special properties, which significantly increases the AP number from (<i>N</i> + 1) to (3<i>N</i> + 1). Increasing the AP number with fewer resonators allows us to increase the selectivity and rejection level and reduce BPF insertion losses. The special properties of resonators are that their input admittance Y has one or two poles (ω<sub>p1</sub>, ω<sub>p2</sub>) located next to the resonance frequency ω<sub>0</sub>. This leads to the appearance of AP in a BPF. We propose and analyze three resonators with special properties. They are formed by a cascade connection of a quarter-wave resonator and lumped <i>L</i> and <i>C</i>. The input of the resonators is located on the side of the lumped elements. It was found that the Q-factors of lumped elements do not affect the filter losses in the passband. The reduction of <i>Q</i><sub><i>L</i></sub> and <i>Q</i><sub><i>C</i></sub> leads only to the decrease of the AP “depth.” For the first time, 7 APs were implemented in the experimental second-order microstrip BPF.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"18 7 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Radioelectronics and Communications Systems","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3103/s073527272311002x","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Engineering","Score":null,"Total":0}
引用次数: 0
Abstract
N-order bandpass filter (BPF) with parallel resonators and cross and mixed couplings can have (N + 1) transmission zeros (TZ) located on the complex plane s = σ + jω. TZs at real frequencies (jω axis) are also called attenuation poles (AP). The authors propose an alternative possibility of AP forming in filters using resonators with special properties, which significantly increases the AP number from (N + 1) to (3N + 1). Increasing the AP number with fewer resonators allows us to increase the selectivity and rejection level and reduce BPF insertion losses. The special properties of resonators are that their input admittance Y has one or two poles (ωp1, ωp2) located next to the resonance frequency ω0. This leads to the appearance of AP in a BPF. We propose and analyze three resonators with special properties. They are formed by a cascade connection of a quarter-wave resonator and lumped L and C. The input of the resonators is located on the side of the lumped elements. It was found that the Q-factors of lumped elements do not affect the filter losses in the passband. The reduction of QL and QC leads only to the decrease of the AP “depth.” For the first time, 7 APs were implemented in the experimental second-order microstrip BPF.
期刊介绍:
Radioelectronics and Communications Systems covers urgent theoretical problems of radio-engineering; results of research efforts, leading experience, which determines directions and development of scientific research in radio engineering and radio electronics; publishes materials of scientific conferences and meetings; information on scientific work in higher educational institutions; newsreel and bibliographic materials. Journal publishes articles in the following sections:Antenna-feeding and microwave devices;Vacuum and gas-discharge devices;Solid-state electronics and integral circuit engineering;Optical radar, communication and information processing systems;Use of computers for research and design of radio-electronic devices and systems;Quantum electronic devices;Design of radio-electronic devices;Radar and radio navigation;Radio engineering devices and systems;Radio engineering theory;Medical radioelectronics.