Abstract

An ultra-wideband bandpass filter formed by cascading of a novel high-pass filter (HPF) and a low-pass filter (LPF) on suspended substrates with a two-sided pattern of strip conductor has been investigated. The high selectivity of the HPF is ensured by the transmission zeros near the passband, the number of which is equal to the filter order. A second-order HPF has been designed on a 0.5-mm-thick substrate with a permittivity of ε = 9.8 using the numerical electrodynamic analysis of a 3D model of the filter. The experimental HPF prototype has a cutoff frequency of f_b = 0.25 GHz at a level of –3 dB and a passband that extends to 5 GHz. The ultra-wideband bandpass filter formed by cascading of the LPF and the designed HPF has a fractional bandwidth of Δf/f₀ = 150% with a central frequency of f₀ = 1 GHz. It has the broad and deep high-frequency stopband, which extends to a frequency of 7.8f₀ at a suppression level of –100 dB.

中文翻译：

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噪声抑制水平超过100 dB的超宽带带状线带通滤波器

摘要

研究了通过在带状导体两侧图案的悬浮基板上级联新型高通滤波器（HPF）和低通滤波器（LPF）形成的超宽带带通滤波器。HPF的高选择性是通过通带附近的传输零来确保的，其数目等于滤波器阶数。使用滤波器的3D模型的数值电动力学分析，已在介电常数ε= 9.8的0.5毫米厚基板上设计了二阶HPF。实验性HPF原型的截止频率为f _b = 0.25 GHz，水平为–3 dB，通带扩展至5 GHz。由LPF和设计的HPF级联形成的超宽带带通滤波器的分数带宽为Δf / f₀ = 150％，中心频率为f ₀ = 1 GHz。它具有宽而深的高频阻带，可在–100 dB的抑制水平下扩展到7.8 f ₀的频率。