scholarly journals Demonstration of Reconfigurable BPFs with Wide Tuning Bandwidth Range Using 3λ/4 Open- and λ/2 Short- Ended Stubs

Technologies ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 14
Author(s):  
Salman Arain ◽  
Abdul Quddious ◽  
Symeon Nikolaou ◽  
Photos Vryonides

In this paper, two implementations of reconfigurable bandwidth bandpass filters (BPFs) are demonstrated both operating at a fixed center frequency of 2.4 GHz. The proposed reconfigurable bandwidth filters are based on a square ring resonator loaded with λg/4 open-ended stubs that are permanently connected to the ring and converted to either 3λg/4 open-ended stubs or λg/2 short-ended stubs by means of positive-intrinsic-negative(PIN) diodes to implement two reconfigurable bandwidth states for each case. Due to the symmetrical nature of the design, even- and odd-mode analysis is used to derive the closed-form to describe the reconfigurable filters’ behavior. The switching between narrowband and wideband is achieved using PIN diodes. In the first implementation (λg/4 open-ended stubs to 3λg/4 open-ended stubs), a reconfigurable bandwidth bandpass filter is proposed where additional out-of-band transmission zeros are generated by integrating a λg/2 open-ended stub at the input port. In the second implementation (λg/4 open-ended stubs to λg/2 short-ended stubs), further improvement in the upper stopband is achieved by utilizing a pair of parallel coupled lines (PCLs) as feeding lines and a pair of λg/4 high impedance short-ended stubs implemented at the input and output ports. To verify the validity of the simulated results, the prototypes of the proposed reconfigurable filters were fabricated. For the first case, measured insertion loss is less than 1.8 dB with a switchable 3-dB fractional bandwidth (FBW) range from 28% to 54%. The measured results for the second case exhibit a low insertion loss of less than 1 dB and a 3-dB fractional bandwidth that can be switched from 34% to 75%, while the center frequency is kept constant at 2.4 GHz in both cases.

2021 ◽  
Vol 36 (7) ◽  
pp. 865-871
Author(s):  
Jin Shi ◽  
Jiancheng Dong ◽  
Kai Xu ◽  
Lingyan Zhang

A novel miniaturized wideband bandpass filter (BPF) using capacitor-loaded microstrip coupled line is proposed. The capacitors are loaded in parallel and series to the coupled line, which makes the filter just require one one-eighth wavelength coupled line and achieve filtering response with multiple transmission poles (TPs) and transmission zeros (TZs). Compared with the state-of-the-art microstrip wideband BPFs, the proposed filter has the advantages of compact size and simple structure. A prototype centered at 1.47 GHz with the 3-dB fractional bandwidth of 86.5% is demonstrated, which exhibits the compact size of 0.003λ2 g (λg is the guided wavelength at the center frequency) and the minimum insertion loss of 0.37 dB.


2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Ziqiang Xu ◽  
Gen Zhang ◽  
Hong Xia ◽  
Meijuan Xu

Hexagonal dual-mode cavity and its application to substrate integrated waveguide (SIW) filter are presented. The hexagonal SIW resonator which can combine flexibility of rectangular cavity and performance of circular cavity is convenient for dual-mode bandpass filters design. By introducing coupling between source and load, the filter not only has good selectivity due to two controllable transmission zeros, but also has a small size by the virtue of its single-cavity structure. A demonstration filter with a center frequency of 10 GHz and a 3 dB fractional bandwidth of 4% is designed and fabricated to validate the proposed structure. Measured results are in good agreement with simulated ones.


2014 ◽  
Vol 7 (6) ◽  
pp. 655-660 ◽  
Author(s):  
Photos Vryonides ◽  
Symeon Nikolaou ◽  
Sangkil Kim ◽  
Manos M. Tentzeris

A reconfigurable band-pass filter with switchable bandwidth, for wireless applications is demonstrated using a dual-mode microstrip square-loop resonator. The proposed filter has been designed on Rogers RO4003C and achieves switchable bandwidth by changing the length of two tuning stubs with the implementation of two strategically placed p-i-n diodes as switching elements. The filter was designed with a center frequency of 2.4 GHz and the two distinct operation states have bandwidths, 113 MHz (4.8%) with an insertion loss of 1.2 dB and 35 MHz (1.5%) with an insertion loss of 1.5 dB. The physical size of the fabricated reconfigurable filter including the implementation of the DC bias lines is comparable to the size of a conventional filter.


2018 ◽  
Vol 38 ◽  
pp. 03039
Author(s):  
Chang Zhou ◽  
Chen Ji ◽  
Gen Ping Wu

A technique for tunable filters with low insertion loss and narrow bandwidth is proposed in the form of comb-line structure. Both resonant capacitor with pin-diodes and resonant inductance in the tunable filter were analyzed and the main source of insertion loss was obtained. A series of filters with same pin-diodes, center frequency, absolute bandwidth and low return loss was simulated. The results showed that, by changing the values of the resonant capacitor and inductance, insertion loss of the filter can be greatly restricted. This technique will allow the design of tunable LC filters with low insertion loss and narrow bandwidth.


2017 ◽  
Vol 9 (10) ◽  
pp. 1931-1936 ◽  
Author(s):  
Kaijun Song ◽  
Yifang Zhou ◽  
Maoyu Fan ◽  
Yu Zhu ◽  
Yong Fan

A wide-stopband bandpass-filtering power divider with high-frequency selectivity has been proposed in this paper. The input and output feeding lines and eight 1/4 wavelength resonators are used to realize the signal transmission. In order to obtain good frequency selectivity, source-load coupling transmission path is used to generate transmission zeros near the passband. A four-way power divider with bandpass-filtering response and high-frequency selectivity is designed, fabricated, and measured. The measured results agree with the simulated ones closely in the desirable frequency range. The measured center frequency of the power divider is 2.38 GHz with input return loss of 31.2 dB, while the measured insertion loss is about 1 dB (not including ideal 6 dB four-way power dividing insertion loss). Moreover, the measured 3-dB bandwidth is 12% and the measured stopband attenuation is >15 dB from 2.59 to 7.7 GHz. In addition, two transmission zeros of 1.9 and 2.8 GHz are located near the passband. The measured output isolations are all >15.7 dB.


2020 ◽  
Vol 20 (1) ◽  
pp. 73-79
Author(s):  
Girdhari Chaudhary ◽  
Yongchae Jeong

This paper presents a design of a transmissive-type, low insertion loss (IL) negative group delay (NGD) circuit with a reconfigurable NGD. The proposed circuit consists of a series transmission lines (TLs) and shunt short-circuited coupled lines where an isolation port is terminated with a parasitic compensated PIN diode. Analytical design equations are derived to obtain the circuit parameters for the predefined NGD and IL. The low IL can be achieved because of the very high characteristic impedance of the short-circuited coupled lines. The TL terminated with a PIN diode is used to achieve the constant center frequency of reconfigurable NGD circuit. For experimental validation, the NGD circuit is designed and fabricated at a center frequency (<i>f</i><sub>0</sub>) of 2.14 GHz. In the measurement, the NGD varies from -0.5 ns to -2 ns with an IL variation of 2.08 to 3.60 dB at <i>f</i><sub>0</sub> = 2.14 GHz. The NGD bandwidth (bandwidth of GD less than 0 ns) varies from 90 MHz to 50 MHz. The minimum input/output return losses are higher than 10 dB for the overall tuning range.


2012 ◽  
Vol 236-237 ◽  
pp. 1383-1388
Author(s):  
Su Ping Li ◽  
Cheng Guo Chang ◽  
Wei Wu

A novel dua1-mode microstrip bandpass filter with two triangle corner cuts and a pair of equal crossed slots is proposed. The performance of the designed filter is studied in detail. The proposed filter structure uses a single patch without coupling gaps. The center frequency is about 2.11GHz. The 3dB relative bandwidth is 9.95%, and the minimum insertion loss in the passband is 0.12dB. Two transmission zeros can be implemented on both sides of the passband. The insertion loss is l0dB within 2.04-2.18GHz. The effect on the filter’s performance by changing filter parameters is studied. The results show that this new filter can provide a low loss and make miniaturization easy.


2014 ◽  
Vol 7 (6) ◽  
pp. 685-690
Author(s):  
Sang-Ho Lee ◽  
Hobyung Yoon ◽  
Jungje Ha ◽  
Yongshik Lee

This work demonstrates design methods that can achieve remarkable enhancement in the stopband response of microstrip coupled-line filters. The frequencies of resonance and/or the transmission zeros of a coupled-line section can be controlled by its length. Therefore, by constructing a filter with coupled lines of incommensurate lengths such that these frequencies do not overlap, substantial improvement in the stopband response can be obtained. Besides its compact structure and simple design procedure, an unprecedented performance is demonstrated experimentally in which the transmission level is maintained below −20 dB up to as high as 11.9 f0 for a third-order filter, where f0 is the center frequency.


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.


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.


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