Realization of transmission zeros for bandpass filter using inductive-coupled stub-loaded resonators

2019 ◽  
Vol 12 (1) ◽  
pp. 34-38
Author(s):  
Fei Cheng ◽  
Ping Lu ◽  
Kama Huang

AbstractThis article proposes a bandpass filter with three controllable transmission zeros (TZs) using three inductive-coupled stub-loaded resonators (SLRs). Different from other works, the proposed SLR can create one transmission pole and one TZ. With the TZs above the passband, high stopband rejection level is achieved. Moreover, the K-inverters are realized by short-circuit stubs between two adjacent SLRs. A general synthesis method for this kind of filter is described. For verification, a filter centered at 2.44 GHz with 0.18 GHz bandwidth is designed. The measured results show that the filter has three TZs at 3.1, 3.9, and 5 GHz. With those TZs, the filter's stopband rejection level is greatly improved.

Frequenz ◽  
2018 ◽  
Vol 72 (9-10) ◽  
pp. 455-458 ◽  
Author(s):  
Vivek Singh ◽  
Vinay Kumar Killamsetty ◽  
Biswajeet Mukherjee

Abstract In this letter, a miniaturized Band Pass Filter (BPF) with wide stopband centered at 0.350 GHz for TETRA band applications is proposed using a Spiral Short Circuit quarter wavelength Stepped Impedance Resonator (SSC-SIR) and a stub loaded on feed line for enhancement of rejection level in the stopband. Spiral configuration of the resonator is used for the miniaturization of BPF. The proposed BPF provides a 3dB fractional bandwidth of 13.7 % with two transmission zeros in the lower and upper stopband to provide good selectivity and four transmission zeros which provide wide stopband upto 6.86f0. Proposed BPF has a very compact size of 0.064λg×0.062λg.


2018 ◽  
Vol 27 (07) ◽  
pp. 1850100 ◽  
Author(s):  
Amit Bage ◽  
Sushrut Das

This paper presents a planar insert-loaded compact, dual-pole, dual-band, waveguide bandpass filter with adjustable multiple transmission zeros. Two identical inserts are placed on the transverse plane of a standard WR-90 waveguide at 8.41[Formula: see text]mm distance to achieve the filter characteristics. The insert consists of a stub-loaded C-shaped resonator and two asymmetric slot resonators. Two stub-loaded C-shaped resonators have been used to achieve dual-pole, dual-band response whereas the asymmetric slot pairs have been used to introduce transmission zeros. The structure allows independent control of the center frequencies of the passbands and transmission zeros, which is useful to control the rejection level of out-of-band signals without disturbing the center frequency. Measured result shows a dual-pole, dual-band, bandpass response with center frequencies at 8.81[Formula: see text]GHz and 10.9[Formula: see text]GHz, the respective 3[Formula: see text]dB bandwidths of 0.276[Formula: see text]GHz and 0.398[Formula: see text]GHz and transmission zeros at 8.02, 8.5, 9.46, 10.13, 11.53 and 12 GHz.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Haiwen Liu ◽  
Baoping Ren ◽  
Xiang Xiao ◽  
Zhichong Zhang ◽  
Shen Li ◽  
...  

A miniaturized bandpass filter (BPF) using defected ground structure (DGS) resonator with the characteristic of harmonic rejection is developed in this paper. The second and third harmonics of the proposed BPF are rejected by the characteristic of stepped-impedance DGS resonator. Moreover, open stubs are established so that two adjustable transmission zeros can independently be created to extend the stopband and improve the rejection level. Finally, a second-order BPF, centered at 1.62 GHz with a stopband extended up to 5.6 GHz and a rejection level better than 20 dB, is designed and implemented for GPS application. A good agreement between simulation and measurement verifies the validity of this design methodology.


2016 ◽  
Vol 9 (3) ◽  
pp. 591-598 ◽  
Author(s):  
Di Lu ◽  
Xiao-Hong Tang

A compact microstrip multi-stub loaded bandpass filter (BPF) with ultra-wide stopband is introduced and investigated. Lumped-equivalent circuit (LEC) method is adopted to analyze the characteristics of the in-band response based upon the low frequency LEC and even-odd mode analytical method. Besides, equivalent transmission line circuit method with even-odd mode analytical method are adopted to discuss the mechanism of the out-band rejection based upon the transmission poles and the transmission zeros analysis of the even-/odd-mode equivalent circuits. Accordingly, the design and the optimization procedures of this type of filters are summarized. To experimentally validate the proposed method, the filter is fabricated and measured. The measured results illustrate this BPF centered at f0 = 2.8 GHz, with −3 dB fractional bandwidth of 109.3%, the insert loss (IL) of less than 1 dB from 1.4 to 4 GHz, and the rejection level of 20 dB from 5.1 to 33.5 GHz(1.82f0 to 11.96f0).


2007 ◽  
Vol 17 (2) ◽  
pp. 890-893 ◽  
Author(s):  
S. Ono ◽  
Y. Harada ◽  
A. Saito ◽  
M. Kimura ◽  
N. Sekiya ◽  
...  
Keyword(s):  

2016 ◽  
Vol 9 (5) ◽  
pp. 1029-1035 ◽  
Author(s):  
Jugul Kishor ◽  
Binod K. Kanaujia ◽  
Santanu Dwari ◽  
Ashwani Kumar

Synthesis of differential-mode bandpass filter (BPF) with good common-mode suppression has been described and demonstrated on the basis of ring dielectric resonator (RDR) for high-performance communication system. A RDR with two pairs of feeding lines has been used to excite TE01δ-mode. This unique combination of feeding lines and the ring resonator creates a differential passband. Meanwhile, TM01δ-mode of the DR can also be excited to achieve common-mode rejection in the stopband. Transmission zeros are created in the lower and upper stopband to further improve the selectivity of the proposed BPF. A second-order differential BPF is designed, fabricated and its performance is measured to validate the concept. There is good agreement between simulated and measured results.


Sign in / Sign up

Export Citation Format

Share Document