Dual band bandpass filter is designed and optimized for RF wireless applications. The performances of that RF dual band filter are improved especially parameters describing the insertion loss, return losses and reject...Dual band bandpass filter is designed and optimized for RF wireless applications. The performances of that RF dual band filter are improved especially parameters describing the insertion loss, return losses and rejection. Dual-band bandpass filter using stub loaded resonators is designed and characterized. Theoretical results are compared with experimental data. This comparison shows that the magnitude of reflection coefficient S11 from ADSTM simulation is better than 28.0 dB, and the insertion loss S21 is less than 0.5 dB. The two rejections are also better than 32.0 dB. The simulated results also show that two central frequencies are located at desired 1.82 and 2.95 GHz. Comparison of measured and simulated results shows frequency drift. The main reason for this frequency shifting is due to some uncertainties. These are obviously due to geometrical and physical parameters H and εr respectively of Duroid substrate used during design and measurements.展开更多
In this paper, the resonant frequency of a dual\|mode dielectric resonator is calculated using a finite difference time\|domain method. A new type of bandpass filter is designed with the calculated coupling coefficien...In this paper, the resonant frequency of a dual\|mode dielectric resonator is calculated using a finite difference time\|domain method. A new type of bandpass filter is designed with the calculated coupling coefficient. The filter designed in this paper has reached the design goal, verified by simulation with Ansoft HFSS.展开更多
A class of new planar dual-mode filters without coupling gaps is proposed. The proposed structures use a single patch wiuhout coupling gaps. Attenuation poles can be implemented on either side of the passband by chang...A class of new planar dual-mode filters without coupling gaps is proposed. The proposed structures use a single patch wiuhout coupling gaps. Attenuation poles can be implemented on either side of the passband by changing the locations of two feed lines. By cutting two corners in the patch, two attenuation poles on both sides of passband are implemented. A novel dual-mode elliptic-function bandpass filter structure without coupling gaps is also proposed. These new filters can provide a low insertion loss and reduce uncertainty in fabrication owing to the absence of coupling gaps.展开更多
This study presents two multimode stepped-impedance structures to design single-and dual-band filters. Transmission zeroes are introduced for the single-band filter by using dual-mode stepped-impedance resonators. The...This study presents two multimode stepped-impedance structures to design single-and dual-band filters. Transmission zeroes are introduced for the single-band filter by using dual-mode stepped-impedance resonators. The single-band filter with high selectivity is centered at 6.02 GHz and has a fractional bandwidth （FBW） of 25.6%. Four stubs （two low frequency and two high frequency ones） are connected to the rectangular patch in the center to construct a quadruple-mode resonator. The independent conditions of the center frequencies of the high and low bands of the resonator are analyzed. A dual-band filter, which operates at 1.53 GHz and 2.44 GHz with FWBs of 12.1% and 14.1%, respectively is designed. The single-and dual-band filters are both fabricated with double-sided YBCO films and they can be used in mobile and satellite communications.展开更多
文摘Dual band bandpass filter is designed and optimized for RF wireless applications. The performances of that RF dual band filter are improved especially parameters describing the insertion loss, return losses and rejection. Dual-band bandpass filter using stub loaded resonators is designed and characterized. Theoretical results are compared with experimental data. This comparison shows that the magnitude of reflection coefficient S11 from ADSTM simulation is better than 28.0 dB, and the insertion loss S21 is less than 0.5 dB. The two rejections are also better than 32.0 dB. The simulated results also show that two central frequencies are located at desired 1.82 and 2.95 GHz. Comparison of measured and simulated results shows frequency drift. The main reason for this frequency shifting is due to some uncertainties. These are obviously due to geometrical and physical parameters H and εr respectively of Duroid substrate used during design and measurements.
文摘In this paper, the resonant frequency of a dual\|mode dielectric resonator is calculated using a finite difference time\|domain method. A new type of bandpass filter is designed with the calculated coupling coefficient. The filter designed in this paper has reached the design goal, verified by simulation with Ansoft HFSS.
文摘A class of new planar dual-mode filters without coupling gaps is proposed. The proposed structures use a single patch wiuhout coupling gaps. Attenuation poles can be implemented on either side of the passband by changing the locations of two feed lines. By cutting two corners in the patch, two attenuation poles on both sides of passband are implemented. A novel dual-mode elliptic-function bandpass filter structure without coupling gaps is also proposed. These new filters can provide a low insertion loss and reduce uncertainty in fabrication owing to the absence of coupling gaps.
基金Project supported by the National Natural Science Foundation of China(Grant No.61371009)the Fund from the Chinese Ministry of Science and Technology(Grant No.2014AA032703)
文摘This study presents two multimode stepped-impedance structures to design single-and dual-band filters. Transmission zeroes are introduced for the single-band filter by using dual-mode stepped-impedance resonators. The single-band filter with high selectivity is centered at 6.02 GHz and has a fractional bandwidth （FBW） of 25.6%. Four stubs （two low frequency and two high frequency ones） are connected to the rectangular patch in the center to construct a quadruple-mode resonator. The independent conditions of the center frequencies of the high and low bands of the resonator are analyzed. A dual-band filter, which operates at 1.53 GHz and 2.44 GHz with FWBs of 12.1% and 14.1%, respectively is designed. The single-and dual-band filters are both fabricated with double-sided YBCO films and they can be used in mobile and satellite communications.
