Compact lowpass filter based on coupled-line hairpin unit

2012 ◽  
Vol 48 (7) ◽  
pp. 379 ◽  
Author(s):  
Feng Wei ◽  
Lei Chen ◽  
Xiao-Wei Shi
Keyword(s):  
2010 ◽  
Vol 46 (1) ◽  
pp. 88 ◽  
Author(s):  
F. Wei ◽  
L. Chen ◽  
X.-W. Shi ◽  
Q.-L. Huang ◽  
X.-H. Wang

ETRI Journal ◽  
2009 ◽  
Vol 31 (3) ◽  
pp. 324-326 ◽  
Author(s):  
Vamsi Krishna Velidi ◽  
Mrinal Kanti Mandal ◽  
Subrata Sanyal

2020 ◽  
Vol 2020 (1) ◽  
pp. 91-95
Author(s):  
Philipp Backes ◽  
Jan Fröhlich

Non-regular sampling is a well-known method to avoid aliasing in digital images. However, the vast majority of single sensor cameras use regular organized color filter arrays (CFAs), that require an optical-lowpass filter (OLPF) and sophisticated demosaicing algorithms to suppress sampling errors. In this paper a variety of non-regular sampling patterns are evaluated, and a new universal demosaicing algorithm based on the frequency selective reconstruction is presented. By simulating such sensors it is shown that images acquired with non-regular CFAs and no OLPF can lead to a similar image quality compared to their filtered and regular sampled counterparts. The MATLAB source code and results are available at: http://github. com/PhilippBackes/dFSR


PIERS Online ◽  
2007 ◽  
Vol 3 (6) ◽  
pp. 948-950 ◽  
Author(s):  
Maria del Castillo Velazquez-Ahum ◽  
Jesus Martel-Villagr ◽  
Francisco Medina
Keyword(s):  

Author(s):  
Kittipong Nithiporndecha ◽  
Chatrpol Pakasiri

Background: A compact complex impedance-transforming balun for UHF frequencies, which is based on a coupled-line structure that matched all ports and provided high output port isolation, was designed in this paper. Methods: A lumped component transformation was used to minimize circuit size. The implemented circuit operated at 433 MHz with the reflection coefficients less than -16 dB at all ports, 0.22 dB amplitude balance and 180° phase balance at the output ports. The signal coupling between the output ports was -16.8 dB. The circuit size is small at 0.032λ. Results: Complex impedance-transforming baluns were designed to operate at 433 MHz. The source impedance at port 1 was set at Zs = 12 - j12Ω and the load impedances at port 2 and 3 were set at ZL = 80 + j30Ω. Conclusion: A compact complex impedance-transforming balun at UHF frequency, with all ports matched and high isolations, was designed and illustrated in this paper.


Author(s):  
E. Faghand ◽  
S. Karimian ◽  
E. Mehrshahi ◽  
N. Karimian

Abstract A new simple computational tool is proposed for the synthesis of multi-section coupled-line filters based on combined modified planar circuit method (MPCM) and transmission line method (TLM) analysis, referred to as MPCM-TLM. Due to its fundamentally simple architecture, the presented tool offers significantly faster optimization of coupled-line filters – for exactly the same initial simulation set-up – than other costly commercially-available tools, giving equally reliable results. Validity and accuracy of the proposed tool have been verified through the design of 3rd, 5th, and 7th order coupled-line filters and comparative analysis between results obtained from the proposed approach and the high-frequency structure simulator. A remarkable 99% time reduction in the analysis is recorded in the case of 7th order filter using the proposed tool, for almost identical results to HFSS. Therefore, it can be confidently claimed that the proposed technique can be used as a reliable alternative to existing complex, costly, processor-intensive CAD tools.


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