جستجوی مقالات مرتبط با کلیدواژه « bandpass filter(BPF) » در نشریات گروه « برق »

In this article a miniaturized ultra-wideband (UWB) bandpass filter (BPF) using the microstrip rectangular ring loaded by two open stubs is presented. The proposed structure consists of two doublet parallel coupling gaps at each side of a microstrip ring. In comparison with some other filters, this structure shows a significantly wider passband due to the introduction of a cross-coupling between the feed lines (input and output) which generates four pairs of transmission poles in the passband. In order to control the transmission poles in the pass band and adjust the transmission poles near the lower and upper edges of the filter, two open stubs have been loaded on the microstrip rectangular ring. Consequently, a compact four poles ultra-wide bandpass filter is designed which exhibits extremely sharp rejection skirts around the target passband. The proposed filter has a passband that covers 3.2 to 10.6 GHz and its measured 3 dB fractional bandwidth is about 107.5%. In order to validate the performance of the proposed technique, the designed UWB band-pass filter is fabricated and experimental verification is provided. A good agreement has been found between the results obtained by simulation and the measurements. Furthermore, rejection level better than 20 dB in upper stopband is extended to around 15 GHz. To our knowledge, the size of the proposed ultra-wideband filter is more compact in comparison with known similar filters.

In this paper, there are three novel bandpass filters (BPFs), consist of single- and dual-band, presented in a same size, which all the filters, have been designed, optimized and finally fabricated and measured, based on a primary structure and using planar microstrip technology. Each of the generated passbands, is resonated by the use of one of the two existing types of resonator structures. The larger resonators, as main-structures of the filter with a stepped-impedance features, by appling 0°-feed structure and electrical coupling in-between, create the first passband at 0.9 GHz. The smaller resonators as sub-structures, with dual-spiral topology, are in the same size and uniform-impedance, and with symmetrical feeding and internal coupling, are embedded in the main-structures to generate and control the higher passband at 1.8GHz. The existence of a cross-coupling between the sub-structures, suppresses any harmonics in the stop-band and generates additional transmission zeros on both sides of the upper passband. Overal dimensions of the innovative filters with a miniaturizing approach, are reduced from 0.163λg*0.09λg to 0.092λg*0.08λg in terms of the guided wavelength, which is the most compacted structure compared with other filters. According to 0.7 dB and 0.5 dB, the obtained insertion losses of the first and second passbands of the dual-band BPF respectively, the lowest losses have been achieved, compared with other examined dual-band BPFs. Finally three prototypes for global systems for mobile communication, were fabricated and measured. A good agreement between the measured and simulated results indicates realizing the goals and ingenious methods of this design.

In this paper, design, simulation and fabrication of compact quad-band bandpass filters (BPF) using Split Ring Resonators (SRR) are presented. These types of filters are inherently narrow bandwidth. The bandwidths of the passbands of the filter are increased using an interdigital capacitor between two adjacent cells of the filter, and by increasing the substrate thickness. A quad-band BPF with center frequencies of 1. 5, 2. 24, 3. 07 and 4. 43 GHz was designed and simulation results show the bandwidths of these bands are 120, 219, 492 and 280 MHz respectively. In order to adjusting the center frequencies and their bandwidths for practical applications, parametric study and required simulations are presented. The proposed structure has sharp passband selectivity, acceptable insertion loss and return loss in each band, and controllable distance between the bands. Final filters (two structures) are implemented on Rogers 5870 substrate, and simulation and measured results are compared. Second fabricated filter has a compact size of that shows 18%, 69% and 43% size compacting in compare with three samples of quad-band filters of other references.

A compact and sharp-rejection ultra-wideband (UWB) microstrip bandpass filter (BPF) is presented. The proposed filter is constructed with multiple-mode resonator (MMR) and split ring resonator (SRR). Moreover, proposed structure consists of two doublets parallel cou-pling gaps at each side of a microstrip ring. In comparison with some other filters, this struc-ture shows a significantly wider passband due to the introduction of a cross-coupling be-tween the feed lines (input and output) which generate four pairs of attenuation zeros in the passband. In order to control the transmission zeros in the pass band and adjust the transmis-sion zeros near the lower edges of the filter, a Short Stub, Loaded on microstrip Rectangular Ring Has Been Used. Also, In order to sharpen the upper edge of the filter, we used SRRs in both side of the doublets parallel coupling gaps that leads to the addition of one extra trans-mission poles at the upper edge of the filter. Consequently, a compact four-zero and one pole ultra-wide bandpass filter is designed which exhibits extremely sharp rejection skirts around the target passband. The proposed filter has a passband covers 2.8 to 10 GHz and its meas-ured 3 dB fractional bandwidth is about 112.5%. Furthermore, rejection level better than 20 dB in upper stopband is extended to around 18 GHz. To our knowledge, the size of proposed ultra-wideband filter is more compact in comparison with known similar filters.

In this paper، a novel microstrip-line ultra-wideband (UWB) bandpass filter (BPF) based on multiple-mode resonator (MMR) is designed، analyzed and simulated. The structure of the proposed MMR constructed by a modified triple-mode stepped-impedance resonator (MSIR) loaded with a folded step-impedance stub (FSIS). This stub-loaded resonator could generate two more resonate modes and two transmission zeros (TZs) simultaneously. Proposed MMR’s dimensions properly tuned so that first five resonate modes of the proposed MMR roughly allocated in the desirable bandpass، i. e. 3. 1-10. 6GHz، as well as two TZs at the edge of the passband، leading to sharp roll-off. Finally، with using aperture-backed interdigital-coupled lines for feeding، an UWB BPF with compact size، high selectivity، good performance in-band، and wide stopbands is obtained. Simulation results are in excellent agreement with UWB BPF ideal case.