New compact quad-passband bandpass filter based on multi-layer substrate technique

2014 ◽  
Vol 7 (6) ◽  
pp. 679-683
Author(s):  
Hung-Wei Wu ◽  
Shih-Hua Huang

A new compact quad-passband bandpass filter (BPF) using multi-mode resonators (MMRs) based on multi-layered substrate technique is proposed. The filter consists of a pair of multi-mode resonators (uniform impedance resonator and stepped impedance resonator) operated at 1.8/3.7 GHz on top layer and the other pair of the multi-mode resonators operated at 2.4/3 GHz on bottom layer. Source–load coupling lines are used to be the input/output (I/O) ports for providing the multi-paths propagations by cross-coupling effects in the filter. Specifically, the operated frequencies of the filter at 1.8/2.4/3/3.7 GHz with bandwidths of 6.7, 8.2, 4.6, and 7.2% are successfully designed and implemented. The proposed filter is useful for the multi-passband filters design, especially when the passbands are needed to be very close.

2019 ◽  
Vol 12 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Daniel Miek ◽  
Michael Höft

AbstractIn this paper, a completely reconfigurable comb-line bandpass filter is presented. Due to the modularity, different standard coupling matrix topologies like the folded form, cascaded triplets, and the cul-de-sac form can be implemented and tested. Circuit-based coupling matrices like the extracted pole topology can easily be realized as well. Different types of input-/output- and cross-couplings can be examined before fabrication of a fixed filter set-up takes place. Furthermore, the proposed filter platform can be used to construct a diplexer. By using different heights of the inner and outer conductor of the coaxial resonators, arbitrary center frequencies in the range between 1 and 4 GHz can be realized. Various types of input couplings are available and proposed here to achieve bandwidths between 10 and 110 MHz. A variety of cross-coupling apertures able to realize transmission zeros are presented as well.


2017 ◽  
Vol 9 (9) ◽  
pp. 1809-1815 ◽  
Author(s):  
Tao Huang ◽  
Zhenhai Shao

In this paper, a novel microstrip bandpass filter is proposed to enhance sideband selectivity, suppress harmonic frequency up to three-order as well as to keep a miniaturized size for frequency synthesizer application. The filter is constructed by four λ/4 folded stepped-impedance resonators (FSIRs) and two λ/2 stepped-impedance resonators at input/output ports to create three pairs of coupling paths and then to produce three cross-coupling transmission zeros (TZs) as well as to achieve a size miniaturization with 96% reduction compared with the conventional filter. By adding a common grounded metallized via hole among four λ/4 FSIRs of the filter, additional four mixed electric and magnetic coupling paths are set to generate extra four TZs. With these seven TZs, the proposed filter achieves a good sideband selectivity and harmonic suppression. Finally, the filter is designed, fabricated, and measured, its measured results are in well agreement with its simulated results.


2013 ◽  
Vol 101 (3) ◽  
pp. 405-409 ◽  
Author(s):  
Wenjie Feng ◽  
Liming Gu ◽  
Wenquan Che ◽  
Haidong Chen

1980 ◽  
Vol 19 (3) ◽  
pp. 247-249
Author(s):  
A. R. Kemal

Input -output analysis is being widely used in developing countries for planning purposes. For a given level of final demand, input-output analysis allows us to project the required level of gross output to ensure consistency of plan. These projections are made on the assumption that the existing production structure is optimal and it implies that an increase in demand will be met through the expansion of domestic output even when it can be satisfied through an increase in imports. On the other hand, according to the semi-input-output method, we do not have to increase the output of international sectors in order to meet the increase in demand because the level and composition of these activities should be determined by comparative- cost considerations. These are the only national sectors in which output must increase in order to avoid shortage. The semi-input -output method has been such a useful and important contribution, yet, regrettably, its influence on the planning models had been rather limited.


Author(s):  
Jason S. Souder ◽  
Parag Mehresh ◽  
J. Karl Hedrick ◽  
Robert W. Dibble

Homogeneous charge compression ignition (HCCI) engines are a promising engine technology due to their low emissions and high efficiencies. Controlling the combustion timing is one of the significant challenges to practical HCCI engine implementations. In a spark-ignited engine, the combustion timing is controlled by the spark timing. In a Diesel engine, the timing of the direct fuel injection controls the combustion timing. HCCI engines lack such direct in-cylinder mechanisms. Many actuation methods for affecting the combustion timing have been proposed. These include intake air heating, variable valve timing, variable compression ratios, and exhaust throttling. On a multi-cylinder engine, the combustion timing may have to be adjusted on each cylinder independently. However, the cylinders are coupled through the intake and exhaust manifolds. For some of the proposed actuation methods, affecting the combustion timing on one cylinder influences the combustion timing of the other cylinders. In order to implement one of these actuation methods on a multi-cylinder engine, the engine controller must account for the cylinder-to-cylinder coupling effects. A multi-cylinder HCCI engine model for use in the control design process is presented. The model is comprehensive enough to capture the cylinder-to-cylinder coupling effects, yet simple enough for the rapid simulations required by the control design process. Although the model could be used for controller synthesis, the model is most useful as a starting point for generating a reduced-order model, or as a plant model for evaluating potential controllers. Specifically, the model includes the dynamics for affecting the combustion timing through exhaust throttling. The model is readily applicable to many of the other actuation methods, such as variable valve timing. Experimental results validating the model are also presented.


Author(s):  
Gaurav Saxena ◽  
Priyanka Jain ◽  
Y. K. Awasthi

Abstract In this paper, a ultra-wideband (UWB) bandpass filter with stopband characteristics is presented using a multi-mode resonator (MMR) technique. An MMR is formed by loading three dumbbell-shaped (Mickey and circular) shunt stubs placed in the center and two symmetrical locations from ports, respectively. Three circular and arrowhead defected ground structures on the ground plane are introduced to achieve UWB bandwidth with a better roll-off rate. The proposed filter exhibits stopband characteristics from 10.8 to 20 GHz with a 0.4 dB return loss. The group delay and roll-off rate of the designed filter are <0.30 ns in the passband and 16 dB/GHz at lower and higher cut-off frequencies, respectively. The dimension of the filter is 0.74λg × 0.67λg mm2 and was fabricated on a cost-effective substrate. All simulated results are verified through the experimental results.


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