scholarly journals To Study The Effect Of Center Frequency And Bandwidth On Quality Factor Of Microstrip Interdigital Bandpass Filter

2012 ◽  
Vol 3 (5) ◽  
pp. 41-42
Author(s):  
Abhishek Kumar Tripathi
2016 ◽  
Vol 6 (6) ◽  
pp. 1294-1296
Author(s):  
N. Soltani

A monolithic tunable low noise active bandpass filter is presented in this study. Biasing voltages can control the center frequency and quality factor. By keeping the gain constant, the center frequency shift is 300 MHz. The quality factor can range from 90 to 290 at the center frequency. By using a noise cancelling circuit, noise is kept lower than 2.8 dB. The proposed filter is designed using MMIC technology with a center frequency of 2.4 GHz and a power consumption of 180 mW. ED02AH technology is used to simulate the circuit elements.


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.


2015 ◽  
Vol 645-646 ◽  
pp. 646-652
Author(s):  
Yan Xiao Zhao ◽  
Wan Rong Zhang ◽  
Hong Yun Xie ◽  
Xin Huang ◽  
Liang Hao Zhang

A second order differential filter with Q-enhancement and tunable active inductor is presented. The design technique for a tunable Q-enhancement SiGe HBT active inductor operating in the wide RF-band for the filter is described. Multi-regulated Cascode circuit is employed to enhance the quality factor Q by increasing the output impedance. Tunable active resistor is introduced to boost the tuning ability of the active inductor. Employing the proposed active inductor, the center frequency of the filter is tuned in the frequency of 1.05~2.45GHz by adjusting the bias current, Q reducing with different bias current can be compensated via tuning the feedback effective resistance of the active inductor, and Q has almost constant value of 209~225 at the frequency of 2.15GHz.


Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 494 ◽  
Author(s):  
Jungah Kim ◽  
Yongho Lee ◽  
Shinil Chang ◽  
Hyunchol Shin

We present a low-power CMOS active-resistance-capacitance (active-RC) complex bandpass filter (BPF) with tunable gain, bandwidth, center frequency, quality factor, and passband flatness for Bluetooth applications. A transfer function analysis for a cross-coupled Tow-Thomas biquad structure is presented to prove that the flatness profile of the passband gain can be effectively controlled by independently tuning two cross-coupling resistors. The proposed biquad-based complex BPF was employed to realize a fourth-order baseband analog processor for a low intermediate frequency (low-IF) RF receiver. The baseband analog processor was composed of two complex biquad filters and three first-order variable-gain amplifiers. It was fabricated in a 65-nm RF CMOS and achieved wide tuning capabilities, such as a gain of −15.6 to 50.6 dB, a bandwidth of 1.4–3.9 MHz, a center frequency of 1.5–4.1 MHz, and a passband flatness of −1 to 1 dB. It also achieved an image rejection ratio of 40.3–53.3 dB across the entire gain tuning range. It consumed 1.4 mA from a 1 V supply and occupied an area of 0.19 mm2 on the silicon substrate. The implementation results prove that the proposed complex BPF was able to effectively enhance the signal processing performances through the flexible and wide-range tunability of the passband flatness, as well as that of the gain, bandwidth, center frequency, and quality factor.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2614
Author(s):  
Qian Yang ◽  
Shuangyang Liu ◽  
Hongyu Shi ◽  
Kai-Da Xu ◽  
Xinyue Dai ◽  
...  

A corrugated disk resonator with eight grooves is proposed for wideband bandpass filter (BPF) design. Due to the spoof localized surface plasmons resonances of the corrugated metallic structure, the dipole, quadrupole, hexapole modes, and a fundamental mode excited by the introduced short-circuited via holes are employed to realize four transmission poles (TPs) in the passband. The theoretical analysis is described by the electric field and current distributions on the resonator. The resonant frequencies can be tuned easily by the parameters of the structure, which can be used to adjust the center frequency and bandwidth of the BPF freely. Furthermore, two resonators are cascaded to obtain eight TPs to improve the selectivity performance. Finally, three fabricated filters demonstrate the design method.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Karthie S. ◽  
Zuvairiya Parveen J. ◽  
Yogeshwari D. ◽  
Venkadeshwari E.

Purpose The purpose of this paper is to present the design of a compact microstrip bandpass filter (BPF) in dual-mode configuration loaded with cross-loop and square ring slots on a square patch resonator for C-band applications. Design/methodology/approach In the proposed design, the dual-mode response for the filter is realized with two transmission zeros (TZs) by the insertion of a perturbation element at the diagonal corner of the square patch resonator with orthogonal feed lines. Such TZs at the edges of the passband result in better selectivity for the proposed BPF. Moreover, the cross-loop and square ring slots are etched on a square patch resonator to obtain a miniaturized BPF. Findings The proposed dual-mode microstrip filter fabricated in RT/duroid 6010 substrate using PCB technology has a measured minimum insertion loss of 1.8 dB and return loss better than 24.5 dB with a fractional bandwidth (FBW) of 6.9%. A compact size of 7.35 × 7.35 mm2 is achieved for the slotted patch resonator-based dual-mode BPF at the center frequency of 4.76 GHz. As compared with the conventional square patch resonator, a size reduction of 61% is achieved with the proposed slotted design. The feasibility of the filter design is confirmed by the good agreement between the measured and simulated responses. The performance of the proposed filter structure is compared with other dual-mode filter works. Originality/value In the proposed work, a compact dual-mode BPF is reported with slotted structures. The conventional square patch resonator is deployed with cross-loop and square ring slots to design a dual-mode filter with a square perturbation element at its diagonal corner. The proposed filter exhibits compact size and favorable performance compared to other dual-mode filter works reported in literature. The aforementioned design of the dual-mode BPF at 4.76 GHz is suitable for applications in the lower part of the C-band.


2018 ◽  
Vol 27 (06) ◽  
pp. 1850090
Author(s):  
Amin Alahyari ◽  
Massoud Dousti ◽  
Mohammad Bagher Tavakoli

In this paper, a new structure for an integrated channelized active filter is proposed. This filter can be used as a channelized bandpass filter and again as a channelized band-stop filter. This is fulfilled by using one biasing voltage. In designing a three-channel bandpass filter, a recursive differential structure is used. Moreover, by subtracting bandpass filter output from an all-pass output, the proposed three-channel band-stop filter is achieved. A wideband amplifier plays the role of an all-pass filter. In addition, to decrease the noise of this filter, a noise-canceling circuit is adopted. By using this circuit, input impedance matching is obtained simultaneously. The center frequencies of the two-mode channelized filter are 2, 4 and 6[Formula: see text]GHz. In each of them, the center frequency is controlled via two biasing voltages. The maximum center frequency shift is 450[Formula: see text]MHz. For designing the proposed circuit, GaAs 0.15[Formula: see text][Formula: see text]m technology is applied. The occupied area is [Formula: see text][Formula: see text]mm2.


Author(s):  
Darine Kaddour ◽  
Jean-Daniel Arnould ◽  
Philippe Ferrari

In this paper, a miniaturized bandpass filter for ultra-wide-band applications is proposed. It is based on the embedding of high-pass structures in a low-pass filter. A semi-lumped technology combining surface-mounted capacitors and transmission lines has been used. The filter design rules have been carried out. Furthermore, two filters having a 3-dB fractional bandwidth of 142 and 150%, centered at 0.77 and 1 GHz, respectively, have been realized for a proof of concept. Measured characteristics, in good agreement with simulations, show attractive properties of return loss (|S11| <−18 dB), insertion loss (<0.3 dB), and a maximum group delay and group delay variation of 2 and 1.3 ns, respectively. A distributed filter based on the same low-pass/high-pass approach has been also realized and measured for comparison. The size reduction reaches 85% for the semi-lumped filter, and its selectivity is improved with a shape factor of 1.3:1 instead of 1.5:1. The semi-lumped filter's drawback is related to a smaller rejection bandwidth compared to the distributed one. To improve the high-frequency stopband, an original technique for spurious responses suppression based on capacitively loaded stubs has been proposed. Even if the performances do not reach that obtained for the distributed approach, with this technique spurious responses are pushed until eight times the center frequency. A sensitivity study vs. critical parameters has also been carried out, showing the robustness of the design.


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