en 5-Antenna Antenna Research Paper Research Paper <span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">This paper presents the design, fabrication, and analysis of a novel turnstile junction-based wideband orthomode transducer (OMT) for Ka-band satellite communication (SATCOM) systems. The proposed OMT integrates a four-stepped cylindrical tuning stub along with optimized E-plane and H-plane bends and an advanced power combiner, significantly enhancing impedance bandwidth, minimizing return loss, and improving polarization isolation-crucial for dual-polarized communication. The incorporation of this stepped tuning strategy provides improved broadband impedance transformation, enabling wide bandwidth operation, low insertion loss, and strong polarization isolation within a manufacturable architecture. Experimental validation demonstrates excellent performance, achieving a return loss better than -30 dB over 17 GHz to 34.6 GHz, isolation exceeding -60 dB, and a low insertion loss of less than 0.18 dB, with a fractional bandwidth of 68.21%. The measured results closely align with simulations, with minor discrepancies attributed to fabrication tolerances. Compared to conventional OMTs, the proposed structure offers superior electrical characteristics, reduced insertion loss, and improved polarization purity, making it a highly efficient and scalable solution for next-generation Ka-band SATCOM applications.</span></span></span> Ortho Mode Transducer (OMT), turnstile junction, Ka-band SATCOM, Isolation, Return loss, Insertion loss. 3981 3981 http://ijeee.iust.ac.ir/browse.php?a_code=A-10-5942-1&slc_lang=en&sid=1 Lingala Srinivas lingala.srinivas@chaitanya.edu.in 1800319475328460017939 1800319475328460017939 No Electronics and Communication Engineering, Chaitanya Deemed to be University Sunil Singarapu sunil.ece@chaitanya.edu.in 1800319475328460017940 1800319475328460017940 Yes Electronics and Communication Engineering, Chaitanya Deemed to be University, Hanamkonda, Telangana, India