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Good Return Loss (good + return_loss)

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Engineering100%

Selected Abstracts

An efficient method for analyzing nonuniformly coupled microstrip lines

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2005
Dengpeng Chen
Abstract This article presents an efficient method for analyzing nonuniformly coupled microstrip lines. By choosing a modal-transformation matrix, the coupled nonlinear differential equations describing the symmetric nonuniformly coupled microstrip lines are decoupled using even- and odd-mode parameters; the original problem is thus transformed into two single nonuniform transmission lines. A power-law function of arbitrary order and having two adjustable parameters is chosen to better approximate the equation coefficients. Closed-form ABCD matrix solutions are obtained and used to calculate the S -parameters of nonuniformly coupled microstrip lines. Numerical results for two examples are compared with those from a full-wave commercial package and experimental ones in the literature in order to demonstrate the accuracy and efficiency of this method. This highly efficient method is employed to optimize a cosine-shape 10-dB codirectional coupler, which has good return loss and high directivity performance over a wide frequency range. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [source]

Broadband Wilkinson balun using pure left-handed transmission line

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2010
Young-Ho Ryu
Abstract Utilizing the opposite phase shift property of a microstrip line (MSL) and a pure left-handed transmission line (PLH TL), the broadband Wilkinson balun is designed. The PLH TL without a right-handed (RH) branch is designed using effectively negative elements obtained by a cross connection of vias to ground. The PLH TL gives inherently phase-advanced response properties because of negative phase velocity, whereas a conventional MSL has a phase-lag response. The property of a broadband left-handed branch of a PLH TL applies to the implementation of broadband balun. The proposed balun has a good return loss, a good isolation between output ports, an equal-power division, and a 180° ± 10° phase difference in a wide fractional bandwidth of ,71%. Furthermore, the wideband balun that has the fractional bandwidth of 107.8% is theoretically designed with the modified PLH TL having four unit cells. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1665,1668, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25242 [source]

Rectangle waveguide to substrate integrated waveguide transition and power divider

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2010
Chao Li
Abstract A novel Ku-band transition and power divider between rectangle waveguide (RWG) and substrate integrated waveguide (SIW) is proposed. This transition and power divider is realized by a radiating metal patch located on the backside of a middle dielectric substrate and a coupling aperture etched on the SIW's ground plane. The transition and power divider is studied both simulatively and experimentally. As reported, low insertion loss of not higher than 0.6 dB and good return loss of ,15 dB may be achieved at the frequency range of 12.1,12.8 GHz. The method to increase the bandwidth is investigated. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 375,378, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24902 [source]

Design of a UWB planar 180° hybrid exploiting microstrip-slot transitions

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2007
A. M. Abbosh
Abstract The article describes the design of a planar 180° hybrid with an ultra wideband (UWB) performance. The device employs two substrates with a common ground plane and various microstrip-slot transitions to achieve in-phase and out-of-phase signal division over an ultra wide frequency range. At the initial stage, simple design guidelines are used but the final dimensions are determined using a full-wave analysis and design software package. The simulated and measured results of the proposed device reveal a well balanced power split accompanied by a very good approximation of ideal 180° and 0° differential phase shift across the band 3.1 to more than 11 GHz. Also low insertion losses, good return loss at all of the four ports, high isolation between the input ports and fine isolation between output ports are noted across this frequency band. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1343,1346, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22472 [source]