Novel ultra-wideband (UWB) bandpass filter using multiple-mode resonator

Abstract

A novel compact microstrip ultra-wideband (UWB) bandpass filter (BPF) is proposed using a multiple-mode resonator (MMR), aiming at transmitting signals in the whole UWB passband. The resonant frequencies of this MMR in the design are properly adjusted equally within the UWB passband. Then, two aperture-backed interdigital coupled-lines at the two sides are introduced for an effective enhancement of the capacitive coupling factor. Transmission zeros can be created at the lower and upper passband edges to improve the passband selectivity greatly. Finally, a microstrip UWB filter with good in-band filtering performance and sharp rejection skirts is simulated and fabricated with good agreement.

Compact Ultra-wideband Bandpass Filter with Wide Fractional Bandwidth and High Skirt Selectivity

“…Compared with the references [16] and [18], the bandwidth of UWB filter is improved by 5% and 8%, respectively. Although it has almost the same fractional bandwidth as in [14], the proposed UWB filter has better skirt selectivity, where the S.F. increased by 0.137.…”

“…In addition, in [10], a rectangular defect ground structure is adopted, whereas in this work, an annular defected ground structure that enhances flatness and reduces the etching area is used. Fig.4 (b) depicts a comparison of the simulated |S 21 | of the proposed UWB BPF against those shown in [10] and [14]. As is shown in Fig.4 (b), there are five modes resonant frequencies, and two transmission zeros, under weak coupling.…”

“…Since the Federal Communication Commission (FCC) first authorized the unlicensed frequency band of 3.1-10.6 GHz for commercial ultra-wideband (UWB) system [1,2] , an ultra-wideband (UWB) bandpass filter (BPF) has become an essential component of a UWB system, which plays a significant role in UWB wireless communication. Lately, many different models have been introduced to develop new UWB bandpass filters, including composite lowpass/highpass filter topology [3] , planar balum [4] , broadside-coupled structure [5] , defected microstrip structure [6] , cross coupling structure [7] , parasitic coupled line [8] , and multiple-mode resonator (MMR) [9][10][11][12][13][14][15] . The above structures have some good performance, such as low insertion loss, wide bandwidth, sharp skirt selectivity and compact size.…”

“…An UWB bandpass filter with fan-shaped stub-loaded MMR and wide stopband was presented in [17], the filter could exhibit wide stopband. Shi et al [14] proposed a modified multiple-mode resonator combined with two aperturebacked interdigital coupled-lines to obtain sharp rejection skirts. Aditi Sengupta et al [18] proposed a miniature sized UWB filter using a dual MMR and a DGS, the simulated resulted could reach a wide fractional bandwidth of 119%.…”

Hybrid Microstrip/Slotline Ultra-Wideband Bandpass Filter with a Controllable Notch Band

“…Many methods have been proposed to design various UWB bandpass filters (BPFs) by using multimode resonators (MMRs) [1,2], multilayer steppedimpedance resonators (SIRs) [3], and stub-loaded resonators [4]. To acquire the desired strong coupling between resonator and feed lines while keeping the gap width between striplines in a moderate scale that can be achieved easily by using PCB process, an aperture-backed parallel-coupled microstrip line with enhanced coupling degree is constructed to allocate the coupling peak [5,6]. For some practical applications, there is a need to avoid the interference from existing wireless communication systems such as wireless local area network in 5.0 GHz band.…”