Mohammad Shahrazel Razalli
Universiti Malaysia Perlis

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A Ku-Band SIW six-port Tan Gan Siang; Siti Zuraidah Ibrahim; Mohd Nazri A. Karim; Aliya A. Dewani; Mohammad Shahrazel Razalli
Indonesian Journal of Electrical Engineering and Computer Science Vol 17, No 1: January 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v17.i1.pp273-280

Abstract

This paper shows a compact fully integrated six-port Substrate Integrated Waveguide (SIW) operating at Ku-Band frequency range. The SIW six-port is formed by combining two SIW power dividers and two SIW couplers, having the benefit of no additional termination is required as this topology has no excessive port. To achieve the optimized design of the six-port, both of the key components; power divider and coupler are primarily designed, fabricated, and measured individually. Y-junction topology is employed on the power divider structure to achieve a compact size. In turn, the coupling coefficient of the two output ports of the SIW coupler are improved by shifting the position of a row of several vias located at the side wall center closer to the side wall. The simulated six port performance provides an advantage of wide bandwidth within Ku-Band across 13 to 17 GHz with a return loss better than 12 dB and transmission coefficient of 7±1.5 dB. The simulated and measured results show good agreement thus validating the prototype. The SIW six-port can find its application in designing a six-port.
PTS Method with Combined Partitioning Schemes for Improved PAPR Reduction in OFDM System Zeyid T. Ibraheem; Md. Mijanur Rahman; S. N. Yaakob; Mohammad Shahrazel Razalli; F Salman; Kawakib K. Ahmed
Indonesian Journal of Electrical Engineering and Computer Science Vol 12, No 11: November 2014
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v12.i11.pp7845-7853

Abstract

Although orthogonal frequency division multiplexing (OFDM) is an efficient wireless transmission system, it suffers from a crucial drawback namely high peak-to-average power ratio (PAPR) that limits transmitter power efficiency. Thus, different PAPR reduction algorithms have been introduced. Partial transmit sequence (PTS) is the most attractive solution which can provide good PAPR reduction performance without distortion. In any PTS system, partitioning of the OFDM frame into disjoint sub-blocks is a significant step. Out of the existing partitioning techniques, adjacent partitioning (AP) is a fairly simple partitioning scheme achieving efficient PAPR reduction performance. This paper presents an enhanced PTS approach that combines two PTS partitioning schemes, adjacent and interleaved partitioning, in order to effectively reduce the PAPR of OFDM systems. With an aim of determining the effects of length variability of adjacent partitions, we performed an investigation into the performances of a variable length adjacent partitioning (VL-AP) and fixed length adjacent partitioning in comparison with the enhanced PTS scheme.