scholarly journals Microstrip Triband Bandstop Fitler with Sharp Stop Band Skirts and Independently Controllable Second Stop Band Response

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Kishor Kumar Adhikari ◽  
Nam-Young Kim

This paper presents a compact planar triband bandstop filter (TBBSF) with compact size and high selectivity. The structure of the filter incorporates two folded trisection stepped-impedance resonators (TSSIRs). One of these resonators is designed to operate at the first and third center frequencies and the other resonator is designed to operate at the second center frequency of the proposed filter. To achieve a compact size filter, alternating impedance lines of the resonators are folded widthwise and also one resonator is embedded within another. Theoretical analysis and design procedures are described, including the synthesis equations for each resonator. The main advantage of the proposed method is that the filter provides flexibility to tune the second center frequency and control the corresponding bandwidth without changing the first and third stop band response. Additionally, several reflection zeros (RZs) are introduced in the pass band to improve its flatness. To demonstrate the feasibility of the proposed design method, both the first and second order TBBSFs were designed, simulated, and fabricated, with center frequencies of 1.92 GHz, 3.55 GHz, and 5.5 GHz.

2013 ◽  
Vol 273 ◽  
pp. 371-374
Author(s):  
Bao Ping Li ◽  
Yan Liang Zhang

Due to the frequency response periodicity of distributed transmission line, microstrip band-pass filter usually produces parasitic pass-band and outputs harmonics away from the center frequency of main pass-band. Based on the study of rectangular ring defected ground structure, a 5-order microstrip LPF(low-pass filter) was designed using the single-pole band-stop and slow-wave characteristics of the rectangular ring DGS(Defected Ground Structure) and SISS(Step-Impedance Shunt Stub) structure. Compared with traditional LPF, this LPF presents the advantages of compact size, low insertion loss, broad stop-band and high steep. It also validates the requirements of miniaturization and high performance for filters.


Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1697
Author(s):  
Ahmed A. Ibrahim ◽  
Wael A. E. Ali ◽  
Mahmoud A. Abdelghany

Two dual-band second-order highly selective band pass filters operated at 3.5/5.5 GHz and 3.5/6 GHz for wireless local area network /worldwide interoperability for microwave access WLAN/WiMAX applications are introduced in this paper. The designed filters are inspired of utilizing two coupled open-loop resonators loaded with stub, spiral resonators and lumped capacitors. The filters are designed based on calculating the desired coupling matrix and the external quality factor. The first and the second filters are designed at the fundamental mode of 3.5 GHz then the first filter is loaded with two spiral resonators in the microstrip line to produce the desired band stop behaviour, which in turn achieves the second pass-band. However, the second band of the second filter is achieved by loading the stub with the lumped capacitors, which controls the second mode. The centre frequency of the second band is adjusted by varying the lumped capacitors values. The two designed filters have insertion loss less than 0.7 dB in the pass-band region, high selectivity with more than 4 transmission zeros and more than 20 dB attenuation level in the stop band region. The suggested filter has compact size and high selectivity with tunability behavior. The two filters are fabricated and measured to validate the simulated results.


2016 ◽  
Vol 9 (4) ◽  
pp. 903-913 ◽  
Author(s):  
Mahmoud Abdelrahman Abdalla ◽  
Zhirun Hu ◽  
Cahyo Muvianto

The design and analysis of meta-material inspired loaded monopole antenna for multiband operation are reported. The proposed antenna consists of multi resonators inspired from half mode composite right/left handed cells, which has a simple structure, compact size, and provides multiband functionalities. As a proof of concept, a triple band antenna covering all possible WiMAX operating bands, has been designed, fabricated, and characterized. The hosting monopole patch itself generates resonance for 3.3–3.8 GHz band, whereas the loaded metamaterial cells add extra resonance frequencies. The loading of two resonator cells introduces two extra resonances for 2.5–2.7 GHz and 5.3–5.9 GHz bands, respectively. The antenna's operating principle and design procedures with the aid of electromagnetic full wave simulation and experimental measurements are presented. The antenna has good omnidirectional patterns at all three bands. The monopole patch size is 13.5 × 6.5 mm2and the whole antenna size (including the feed line) is 35 × 32 mm2. Compared with conventional single band microstrip patch radiator, the radiator size of this antenna is only 8.5% at 2.5 GHz, 17% at 3.5 GHz, and 37% at 5.5 GHz.


2016 ◽  
Vol 09 (02) ◽  
pp. 1650034 ◽  
Author(s):  
Junning Gao ◽  
Zhibiao Hao ◽  
Lang Niu ◽  
Lai Wang ◽  
Changzheng Sun ◽  
...  

This paper reports surface acoustic wave (SAW) devices fabricated on AlN epitaxial film grown on sapphire, aiming to avoid the detrimental polarization axis inconsistency and refrained crystalline quality of the normally used polycrystalline AlN films. Devices with center frequency of 357 MHz and 714 MHz have been fabricated. The stop band rejection ratio of the as-obtained device reaches 24.5 dB and the pass band ripple is profoundly smaller compared to most of the reported AlN SAW devices with the similar configuration. Judging from the rather high edge dislocation level of the film used in this study, the properties of the SAW devices have great potential to be improved by further improving the crystalline quality of the film. It is then concluded that the AlN epitaxial film is favorable for high quality SAW devices to meet the high frequency and low power consumption challenges facing the signal processing components.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Zh. Yao ◽  
C. Wang ◽  
N. Y. Kim

A dual-mode broadband bandpass filter (BPF) with multiple controllable transmission-zeros using T-shaped stub-loaded resonators (TSSLRs) is presented. Due to the symmetrical plane, the odd-even-mode theory can be adopted to characterize the BPF. The proposed filter consists of a dual-mode TSSLR and two modified feed-lines, which introduce two capacitive and inductive source-load (S-L) couplings. Five controllable transmission zeros (TZs) can be achieved for the high selectivity and the wide stopband because of the tunable amount of coupling capacitance and inductance. The center frequency of the proposed BPF is 5.8 GHz, with a 3 dB fraction bandwidth of 8.9%. The measured insertion and return losses are 1.75 and 28.18 dB, respectively. A compact size and second harmonic frequency suppression can be obtained by the proposed BPF with S-L couplings.


Frequenz ◽  
2019 ◽  
Vol 73 (5-6) ◽  
pp. 209-217 ◽  
Author(s):  
Dinghong Jia ◽  
Quanyuan Feng ◽  
Qianyin Xiang

Abstract This letter presents an approach to design two-pole source-load coupling and four-pole cross-coupling substrate integrated waveguide (SIW) bandpass filters based on multilayer process. Utilizing the field distribution, the vertical magnetic and electric coupling of fundamental mode is designed by suppressing the first spurious mode. Then, source-load and cross-coupling schemes are realized with controllable features in two-pole and four-pole filters, respectively. The harmonic passband produced by TE102 mode can be suppressed by proper coupling technique enabling the connection with TE102 mode in two- and four-pole filter designs, respectively. Three transmission zeros, which are derived from source-load coupling, are introduced around the passband of two-pole filter to improve its selectivity. In the four-pole filter design, a six-order cross-coupling scheme including source and load produces four transmission zeros around the passband, leading to a sharp selectivity. In addition, another transmission zero is generated at the adjacent location of the passband to improve the out-of-band rejection. Compared with conventional horizontally coupled filters made of single layer, the proposed filters show a compact size. To demonstrate the proposed design method, a two-pole and a four-pole double-layered SIW bandpass filters are fabricated and measured. Measured results show that the proposed filters exhibit high selectivity and good out-of-band rejection, as well as a good agreement between simulated and measured results.


Frequenz ◽  
2020 ◽  
Vol 74 (1-2) ◽  
pp. 53-59
Author(s):  
Qingchun Cao ◽  
Hui Liu ◽  
Li Gao

AbstractThis paper presents a compact quad-band bandpass filter. The filter is realized by multi-embedded stub-load resonators. By utilizing multi-embedded structure, the whole filter exhibits a compact size. And due to the multi-section stub-loaded lines, four passbands can be realized and the center frequency of the four passbands can be controlled individually to accommodate different communication protocols. Moreover, by using 0° degree feed structure, there are two transmission zeros locates at left and right side of a passband, which greatly enhance the selectivity. To validate the proposed idea, a quad-band bandpass filter, which operates at 2/2.7/3.45/4.55 GHz is implemented. The insertion loss is smaller than 2 dB and return loss is better than 10 dB. Good agreement between the predicted and measured results demonstrates the proposed idea.


Author(s):  
Б.А. Беляев ◽  
А.М. Сержантов ◽  
Ан.А. Лексиков ◽  
Я.Ф. Бальва ◽  
Р.Г. Галеев

A new monolithic design of a miniature bandpass filter has been developed for the multilayer PCB technology fabrication. The use of multi-conductor stripline resonators in the design provides not only miniaturization, but also high selectivity of the device, which is demonstrated on a prototype filter of the fourth order. The center frequency of the passband of the manufactured filter is f0 = 546 MHz, the fractional bandwidth is Δf / f0 = 25%, the insertion loss is 0.8 dB. The filter has an extended high-frequency stop band, which at a level of ‒30 dB extends up to a frequency of 10f0. The dimensions of the filter are 15.0×12.0×4.3 mm3 (0.027λ0×0.021λ0 ×0.007λ0, where λ0 is the wavelength in vacuum at the frequency f0), and its mass is only 1.8 g. The filter's characteristics and ease of construction for surface mounting prove its high prospects.


2021 ◽  
pp. 553-558
Author(s):  
Cleophas D. K. Mutepfe ◽  
◽  
Viranjay M. Srivastava

A fourth-order Substrate Integrated Waveguide (SIW) filter has been presented in this research work. The four Eighth-Mode (EM) SIW cavity resonators have been electrically coupled and source to load coupling has been achieved by a slight modification of the eighth-mode resonator cavity. Here a 87.5% size reduction has been achieved using the EMSIW, which plays a significant role in achieving miniaturized structure. The operating center frequency is 13.5 GHz with a 3dB bandwidth of 0.5 GHz. The Rogers-5880 substrate has been utilized with relative permittivity of 2.2. The results show that the filter has three transmission zeros on either side of the pass-band, which gives high selectivity and a high out of band rejection.


2019 ◽  
Vol 12 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Qing Liu ◽  
Dongfang Zhou ◽  
Dewei Zhang ◽  
Chenge Bian ◽  
Yi Zhang

AbstractThis paper reports a novel fourth-order quasi-elliptic bandpass filter (BPF) based on capacitive-loaded eighth-mode substrate integrated waveguide (CLEMSIW) cavities. The CLEMSIW cavity is constructed by the conventional eighth-mode SIW with two dielectric substrates and three metal layers; a metal via is employed to connect the middle and bottom metal layers. The middle metal layer achieves a large loading capacitance to shift the resonance frequency. The proposed filter is designed in a quadruple scheme, and two controllable finite-transmission zeros can be realized. For the demonstration, a prototype with a center frequency of 1 GHz and a fractional bandwidth of 10% was designed, fabricated, and measured. The measured results agree well with simulated ones. The proposed filter has advantages of ultra-compact size, high selectivity, and good stopband performances.


Sign in / Sign up

Export Citation Format

Share Document