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Development and optimization of new waveguide polarizers with conducting stepped-thickness septum were performed in the article. Matching and polarization performance of novel microwave devices were accurately modelled using numerical finite elements method. An experimental prototype of the developed waveguide polarization converter with the suggested configuration of a septum was manufactured and measured. It was demonstrated that the application of a stepped-thickness conducting septum with 3 sections instead of a constant-thickness conducting septum improves return losses and cross-polarization isolation of the square waveguide polarization converter by 5 and 7 dB, respectively. In addition, measured cross-polarization isolation of the developed septum waveguide polarizer in an assembled antenna feed network is > 30 dB. Therefore, designed compact stepped-thickness septum polarization converter can be effectively applied in modern dual-polarization antenna systems for satellite communications and radar appliances. [ABSTRACT FROM AUTHOR]

This paper demonstrates the feasibility of very compact and broadband square waveguide bends able to transmit both linear and circular polarizations. A careful control of the bend profile for dual-linear polarization or the use of a new septum-polarizer-like geometry for dual-circular polarization allows to reach full band operation ~34% in the first case and broadband operation ~20% for the second application. Experimental validations show excellent agreement with the theoretical predictions thus effectively extending the previous bandwidth limitations. [ABSTRACT FROM PUBLISHER]

A septum polarizer influenced by inserting short stubs inside the waveguide is studied. Several configurations of stub insertion are investigated to exhibit their physical behaviors. Numerical results show that proper stub insertions may provide additional freedoms to optimally design the polarizer with a better return loss and a flexible phase tuning, which is particularly useful to compensate the deficiency of an imperfect horn antenna to radiate good circularly polarized fields. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 269–273, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23982 [ABSTRACT FROM AUTHOR]