Compact UWB bandpass filter based on simple radial stub resonator structure

Abstract

In this letter, a new compact microstrip ultra‐wideband (UWB) bandpass filter (BPF) is proposed. Using a new electrical model leading to a simple structure based on radial stub resonator (RSR), its originality resides in its noteworthy simple design approach where the filter response can be accurately adjusted by tuning three parameters only. The fabricated filter shows a good agreement between simulations and measurements whereas fulfilling UWB requirements, i.e., enhanced selectivity, good matching and flatness within the entire band of operation, and sufficiently constant group delay. With an overall size of 9.53 mm x 8.28 mm, a high compactness has been achieved, making this structure one of the most compact filters ever reported. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1707–1710, 2016

A Pythagorean tree fractal shape stub-loaded resonator as a UWB bandpass filter with wide stopband

“…The basic unit of this fractal geometry is a square. The name of the fractal geometry reveals that the geometry is inspired by the Pythagorean Theorem [14]. The construction of this fractal geometry starts with a square of area ( S × S ).…”

“…The compact quintuple-mode UWB BPF is reported in [11] with five resonant modes and two TZs are created at both the cut-off frequencies to increase filter's selectivity. Radial stubs [12] loaded multi-mode resonators have been used to design UWB BPF [13, 14]. In this paper, the Pythagoras fractal tree [15] is used as a stub to create a novel multimode resonator.…”

A Reconfigurable UWB Bandpass Filters with Embedded Multi-Mode Resonators

“…It was necessary to explore alternative concepts because of the increasing demand for each of high-performance filters, circuit integration and reduced size [2]. The size of the filter can be reduced by reducing the resonator circuit with modifying its physical structures [3] [4]. Each of the conventional parallel coupled lines band-pass filter [5], U-shape resonators [6], open loops [7], and hairpin filters [8] helped in size reduction.…”

Novel compact ultra‐wideband bandpass filter based on vialess vertical CPW/microstrip transitions

“…As one of important passive components in UWB system, in recent years, many design methods have been applied to the design of UWB bandpass filters (BPFs). In [1][2][3], multiple-mode microstrip resonator (MMR) combines interdigital input/output coupled lines and are utilised to obtain the UWB characteristics. Further, to achieve the required strong coupling, defected ground structure also etched on ground plane under the input/output ports in [2,3].…”

“…In [1][2][3], multiple-mode microstrip resonator (MMR) combines interdigital input/output coupled lines and are utilised to obtain the UWB characteristics. Further, to achieve the required strong coupling, defected ground structure also etched on ground plane under the input/output ports in [2,3]. However, two obvious defects of the filters based on MMR are bad return loss in passband and poor low-frequency selectivity.…”