High Selectivity Broadband Bandpass Filter Using Stub-Loaded Quadruple-Mode Resonator (original) (raw)
Related papers
Bandpass Filter With Tunable Bandwidth Using Quadruple-Mode Stub-Loaded Resonator
IEEE Microwave and Wireless Components Letters, 2012
In this letter, a novel quadruple-mode resonator bandpass filter (BPF) with tunable bandwidth is proposed. By using two types of microwave varactors to tune the resonant frequencies and transmission zeros (TZs), the high-side edge of the passband and low-side edge of the passband can be separately varied. Therefore, the bandwidth could be tunable with reasonable adjust of the values of varactors. Theoretical expressions have been derived for the resonant frequencies and the TZs. The measured results of the BPF show that the fractional bandwidth can be tuned from 22% to 34% at a fixed centre frequency 2.0 GHz with a return loss better than 12 dB. The tested results show good agreement with simulated results.
A Very Compact Quintuple Band Bandpass Filter Using Multimode Stub Loaded Resonator
Progress In Electromagnetics Research C, 2019
This paper presents a very compact quintuple band bandpass filter utilizing multimode stub loaded resonator. A single symmetric resonator is loaded with a short ended stub at the middle along with four pairs of open-ended stubs. The open-ended stubs are folded towards each other in order to make the design more compact and improve the selectivity of the bandpass filter. Because of symmetry, the circuit is analyzed with the help of even-odd mode analysis. The proposed bandpass filter operates
Journal of Electrical Engineering & Technology, 2019
A compact and high-rejection ultra-wideband (UWB) microstrip band-pass filter is proposed by using the multi-mode resonator (MMR) technique. The proposed MMR structure is realized by three open stubs-loaded and two short stubs-loaded and a high impedance microstrip line. Five modes, including two odd modes and three even modes could be designed within the UWB band. By resizing the dimensions of the stubs, the resonant modes of the MMR structure are arranged wider bandpass which the passband selectivity with this configuration significantly improved. By this configuration, the even modes can be flexibly controlled, while the odd modes remain the same. The proposed filter has a passband covers 4.1-10.6 GHz and its measured 3 dB fractional bandwidth is about 89%. In order to validate the performance of the proposed technique, the designed UWB band-pass filter is fabricated and the experimental verification is provided. A good agreement has been found between simulation and measurement's results. To our knowledge, the size of the proposed UWB filter is small in comparison with known similar filters.
Design of compact triple-mode bandpass filter using double center stubs-loaded resonator
Microwave and Optical Technology Letters, 2010
A compact microstrip triple-mode bandpass filter using half-wavelength (k/2) open-ended microstrip line with double center loaded stubs is proposed in this article. By introducing a radial-line stub to the traditional dual-mode resonator, a triple-mode resonator is realized and the mode characteristics of the resonator are discussed. Also, an equivalent lumped circuit is proposed and the method of parameters extracting is given. The proposed filter exhibits a quasielliptic function response with a compact circuit dimension. At last, an experimental filter is fabricated and a good agreement between simulations and measurements is reached.
International Journal of Microwave and Wireless Technologies, 2016
bukuru denis, kaijun song and fan zhang A compact dual-band bandpass filter using stub-loaded stepped impedance resonator (SLSIR) with cross-slots is presented. The symmetric SLSIR is analyzed using even-and odd-mode techniques. Design equations are derived and they are used to guide the design of the circuits. Two passbands can be easily tuned by cross-slots and open stubs. Transmission zeros among each passbands are created, resulting in high isolation and frequency selectivity. An experimental circuit is fabricated and evaluated to validate the design concept. The fabricated filter is compact with 19.76 × 12.7 mm 2. The measurement results are in good agreement with the full-wave simulation results.
Compact Dual-Band Bandpass Filter Based on Stub-Loaded Rectangular Loop Stepped Impedance Resonator
International Journal of Electromagnetics (IJEL)
This work presents a compact dual-band bandpass filter (BPF) based on stub-loaded rectangular loop stepped impedance resonator (SLRLSIR). The proposed SLRLSIR consists of two outer open-circuited and two inner open-circuited stubs, which are designed to the central sides of the rectangular loop resonator. Owing to its symmetry, even-and odd-mode analysis methods are applied to deduce the equivalent-circuit equations and to justify the structural design. The second passband can be easily tuned by changing the two inner open-circuited stubs when the first passband is fixed at a desirable frequency. The upper stopband is improved by a pair of additional open-circuited stubs stepped impedance resonators at the I/O ports. Transmission zeros are generated between passbands and stopbands. A SLRLSIR prototype dual-band BPF with central frequencies of 2.42/4 GHz is fabricated and systematically studied. The measurement results agreed well with the simulation results.
SN Applied Sciences, 2019
A compact tri and quad band band-pass filters (BPFs) utilizing stub loaded resonators is presented for wireless applications. The proposed resonator has been designed and analyzed using even-odd mode analysis due to its symmetrical geometry. Open-ended stubs are loaded at an appropriate position in the dual-mode resonator to achieve tri and quad passbands. To reduce the circuit size and create transmission zeros at our desired frequencies, a symmetrical meandered shape resonator is loaded with open-ended identical stubs which are bent towards each other. The proposed BPFs are tune to operate at GSM (900 MHz), LTE (2300 MHz), WiMAX (3.5 GHz), and WLAN (5.4 GHz) bands. Significant improvements are observed in terms of circuit size, 3-dB fractional bandwidth, insertion loss, and transmission zeros. To check the validity of the proposed tri and quad BPFs, these are simulated, fabricated and measured. The simulated and measured results are compared and strong agreement is observed. The proposed filters can be prospective candidates for wireless communication applications. Keywords Stub loaded resonators (SLR) • Band-pass filters (BPFs) • Triple BPF • Quad BPF • Even and odd mode analysis • WLAN (wireless local area network) • WiMAX (worldwide interoperability for microwave acces) • LTE (long term evolution)
A quintuple mode resonator based bandpass filter for ultra-wideband applications
Microsystem Technologies, 2019
This paper presents a new configuration of quintuple mode resonator for designing a bandpass filter for ultra-wideband applications. The multiple-mode resonator is constituted by two capacitive ended rectangular stubs and connected with a high impedance microstrip line. Inter-digital coupled feed lines are designed to excite the resonator. Standard analytical approach based on odd-/even-mode analysis is applied to examine the resonant characteristics of the multi-mode resonator. The proposed filter has the characteristics of low insertion loss, wide stopband along with compact size. The bandwidth (|S 11 | B-10 dB) of the proposed filter has been observed to vary from 3.11 to 10.63 GHz with low insertion loss value uniform around-0.8 dB. A wide stopband with attenuation of more than 15 dB (11.27-20 GHz) is observed for the proposed design. The filter occupies a compact area equal to 23.4 mm 9 10 mm (about 0.43k g 9 0.09k g , where k g is the guided wavelength at 6.85 GHz). The simulated results agree well with the measured results validating the effectiveness of the work.
Compact dual-band bandpass filter using coupled three-line microstrip structure with open stubs
2011 4th IEEE International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, 2011
A quad-mode resonator is proposed for novel design of dual-band bandpass filters (DBBPFs) with good selectivity and compact size. The symmetrical resonator consists of a pair of coupled line sections (CLSs) and a transmission line section (TLS). Odd-/even-mode method is used to clarify the mode characteristics. Four excited resonant modes are applied to produce two passbands. The frequency ratio range can be adjusted by the CLSs, and the bandwidths can be controlled by the TLS. After installing a pair of U-shape coupling arms, a DBBPF with five transmission zeros (s) around the two passbands are designed and fabricated. The measured results are in good agreement with the simulated results, demonstrating that the proposed filter is feasible in practical use.
Multiwideband Bandpass Filter Based on Folded Quad Cross-Stub Stepped Impedance Resonator
International Journal of Antennas and Propagation
A multiwideband bandpass filter (MW-BPF) using a quad cross-stub stepped impedance resonator (QC-SSIR) was simulated, fabricated, and measured. The proposed QC-SSIR is designed on a four-series arrangement of crossed open stub (COS) structures where each open stub is developed with a step impedance resonator (SIR) structure to generate a wide bandwidth. Compared to the COS resonator, the QC-SSIR has a wider fractional bandwidth and good transmission coefficients and is compact. ABCD matrix analysis is used to investigate the filter structure. Furthermore, the MW-BPF is designed on an FR4 microstrip substrate with εr = 4.4, thickness h = 1.6 mm, and tan δ = 0.0265. The results show that the proposed MW-BPF using a QC-SSIR achieves transmission coefficients/fractional bandwidths of −0.60 dB/49.3%, −1.49 dB/18.7%, and −1.93 dB/13.9% at 0.81 GHz, 1.71 GHz, and 2.58 GHz, respectively. Furthermore, to reduce the filter size, a folded QC-SSIR (FQC-SSIR) structure was also proposed. The res...