scholarly journals A Low-Cost Microwave Filter with Improved Passband and Stopband Characteristics Using Stub Loaded Multiple Mode Resonator for 5G Mid-Band Applications

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 450
Author(s):  
Falih M. Alnahwi ◽  
Yasir I. A. Al-Yasir ◽  
Abdulghafor A. Abdulhameed ◽  
Abdulkareem S. Abdullah ◽  
Raed A. Abd-Alhameed

This paper presents the design and implementation of a printed circuit microwave band-pass filter for 5G mid-band applications, using a Stub Loaded Multiple Mode Resonator (SL-MMR) technique. The objective of this article is to introduce a low-cost microstrip filter with improved passband and stopband characteristics, based on a mathematical analysis of stub loaded resonators. The filter cost is reduced by selecting the low-cost FR4 dielectric material as a substrate for the proposed filter. Based on the transmission line model of the filter, mathematical expressions are derived to predict the odd-mode and the even-mode resonant frequencies of the SL-MMR. The mathematical model also highlights the capability of controlling the position of the SL-MMR resonant frequencies, so that the 5G sub-band that extends along the range (3.7–4.2 GHz) can perfectly be covered with almost a flat passband. At the resonance frequency, a fractional bandwidth of 12.8% (500 MHz impedance bandwidth) has been obtained with a return loss of more than 18 dB and an insertion loss of less than 2.5 dB over the targeted bandwidth. Furthermore, a pair of parasitic elements is attached to the proposed filter to create an additional transmission zero in the lower stopband of the filter to enhance the suppression of the filter stopband. The measured and simulation results are well agreed, and both reveal the acceptable performance of the stopband and passband characteristics of the filter.

2019 ◽  
Vol 4 (7) ◽  
pp. 28-30
Author(s):  
William Johnson ◽  
Cavin Roger Nunes ◽  
Savio Sebastian Dias ◽  
Siddhi Suresh Parab ◽  
Varsha Shantaram Hatkar

In this paper, a dual band microstrip bandpass filter has been proposed utilizing three edge coupled resonators, interdigital stubs and DGS technique. To enhance the coupling degree, two interdigital coupled feed lines are employed in this filter. The suppressing cell consists of stepped impedance ladder type resonators, which provides a wide stopband. The proposed suppressing cell has clear advantages like low insertion loss in the passband and suitable roll off. The frequency response of the filter looks like a standard dual band band-pass filter. The filter exhibits a dual passband with resonant frequencies at 2.2GHz and 3.45GHz covers LTE1 and LTE22 bands.


Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4140
Author(s):  
Maoxiang Hou ◽  
Jun He ◽  
Xizhen Xu ◽  
Ziliang Li ◽  
Zhe Zhang ◽  
...  

We propose and demonstrate a cascaded hollow-core fiber (HCF) device for multi-parameter sensing based on the combination of antiresonant reflecting guidance (ARRG) and Mach-Zender interference (MZI). The device was fabricated by splicing two sections of HCF together. Two sets of fringes, which have different free spectral ranges, were generated from ARRG and MZI, respectively, and were aliasing in the transmission spectrum. The two sets of fringes were then separated using a band pass filter and a Gaussian fitting technique. The wavelengths at two transmission loss dips formed by ARRG and MZI exhibit a temperature sensitivity of 14.1 and 28.5 pm/°C, and a strain sensitivity of 0.4 and −0.8 pm/με, respectively. By using a crossing matrix with differences sensitivities, the cross-sensitivity between temperature and strain can be solved. The gas pressure response of the cascaded HCF device was also tested up to 300 °C, and linear relationships between the gas pressure sensitivities and temperature were found, which can be used in gas pressure application in various temperatures. Moreover, the proposed cascaded HCF sensor is compact, low cost, and simple for fabrication, and hence offers a promising way for the simultaneous measurement of multiple parameters, such as temperature, strain, and gas pressure.


Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2853
Author(s):  
Satheeshkumar Palanisamy ◽  
Balakumaran Thangaraju ◽  
Osamah Ibrahim Khalaf ◽  
Youseef Alotaibi ◽  
Saleh Alghamdi

In this paper, a compact bandpass filter with improved band stop and band pass characteristics for wireless applications is built with four internal conductive poles in a single resonating cavity, which adds novel quad-resonating modes to the realization of band pass filter. This paper covers the design and testing of the S-band combline coaxial cavity filter which is beneficial in efficient filtering functions in wireless communication system design. The metallic cavity high Q coaxial resonators have the advantages of narrowband, low loss, better selectivity and high potential for power handling, as compared to microstrip filter in the application to determine the quality factor of motor oils. Furthermore, the tuning of coupling screws in the combline filter allows in frequency and bandwidth adjustments. An impedance bandwidth of 500 MHz (fractional bandwidth of 12.8%) has been achieved with an insertion loss of less than 2.5 dB and return loss of 18 dB at the resonant frequency. Four-pole resonating cavity filters have been developed with the center frequency of 4.5 GHz. Insert loss at 0 dB and estimated bandwidth at 850 MHz and a quality factor of 4.3 for the band pass frequencies between 4 and 8 GHz is seen in the simulated result.


Frequenz ◽  
2015 ◽  
Vol 69 (9-10) ◽  
Author(s):  
Lei Chen ◽  
Feng Wei

AbstractA compact quad-band microstrip band-pass filter (BPF) using quad-mode stub loaded resonators (SLRs) is presented in this paper. The proposed SLR can achieve quad-band responses analyzed by the odd-even-mode method and have great flexibility to adjust the resonant frequencies. Based on the analysis, a quad-band filter centred at 1.57, 2.5, 3.5 and 5.2 GHz is designed and fabricated. The predicted results on S parameters are compared with the measured ones and good agreement is observed.


2008 ◽  
Vol 22 (29) ◽  
pp. 2843-2848 ◽  
Author(s):  
LI-MING SI ◽  
XIN LV

A novel terahertz (THz) waves band-pass filter with the center frequency of 880 GHz and low insertion loss using microstrip line hairpin resonators is introduced. The properties of this filter are investigated by finite element method (FEM) simulations. The numerical result shows that the filter has a 3 dB bandwidth from 865 GHz to 892 GHz and has 80 GHz bandwidth better than -10 dB. Resonance frequency shifts of the filter covered by dielectric materials of different permittivity and thickness are calculated, which shows that this type of filter is suitable for detecting the properties of overlaid dielectric materials.


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