On a class of low-reflection transmission-line quasi-gaussian low-pass filters and their lumped-element approximations

Abstract

Gaussian-like filters are frequently used in digital signal transmission. Usually, these filters are made of lumped inductors and capacitors. In the stopband, these filters exhibit a high reflection, which can create unwanted signal interference. To prevent that, a new low-reflection ladder network is introduced that consist of resistors, inductors, and capacitors. The network models fictitious transmission lines with Gaussian-like amplitude characteristics. Starting from the analysis of this network, a procedure is developed for synthesis of a new class of lumped-element RLC filters. These filters have transmission coefficients similar to the classical Bessel filters. In contrast to the Bessel filters, the new filters exhibit a low reflection both in the stopband and passband, they have a small span of element parameters, and they are easy for manufacturing and tuning.

Application of Memristors in Microwave Passive Circuits

“…14, is suppressed by insertion of the memristor. LTspice model of the lossy quasi-Gaussian lowpass filter proposed by Djordjević et al [40] is shown in Fig. 19.…”

High-Order Dual-Port Quasi-Absorptive Microstrip Coupled-Line Bandpass Filters

“…Low-Q lossy resonators are also used to achieve either one-port absorption [18]- [20] or symmetrical two-port absorption [21]- [25] for bandstop filters. Quasi-Gaussian lowpass filter prototypes are reported with both ports reflectionless because of the lossy components in the circuit [26], [27]. A 3.0-GHz distributed quasi-absorptive BPF is presented in [28] by using resistor-loaded lossy resonators as its first resonator to absorb reflection at only one side.…”

Synthesis of Absorption Reflectionless Bandstop Filter and Its Design Using Multi-Layer Self-Packaged SCPW

“…In practical circuit design, it is impossible to make RL/S 11 equals infinity, however, it is feasible to enhance the attenuation of S 11 for reducing the reflection to the source. The reflectionless filters [1][2][3][4][5][6][7][8] have been overlooked in the past time until recent years they obtain more and more attention.…”