Tommi Hariyadi, Tommi
Universitas Pendidikan Indonesia

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Journal : TELKOMNIKA (Telecommunication Computing Electronics and Control)

Performance of Groundplane Shaping in Four-Element Dualband MIMO Antenna Subuh Pramono; Tommi Hariyadi; Budi Basuki Subagio
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 15, No 1: March 2017
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v15i1.5002

Abstract

This work presents performance of groundplane shaping and its effect in four element dualband multiple input multiple output (MIMO) antenna. This proposed four element dualband MIMO antenna consists of four bowtie dipole antenna which operates at 1800 MHz (low frequency) and 2300 MHz (high frequency). This proposed four element dualband MIMO antenna occupies a 270 x 210 x  100 mm3  of FR 4 substrate. We use four types  of groundplane pattern i.e. full groundplane, cornered spatial groundplane,crossed middle groundplane, and spiral groundplane. These various grounplane patterns influence the performance of main parameters of dualband MIMO antenna. Cornered spatial groundplane pattern yields a largest bandwidth (VSWR ≤ 2) 282 MHz or 15.24% of center frequency at low frequency. Full groundplane pattern creates 135.2 MHz at high frequency. In addition, cornered spatial groundplane pattern also generates a lowest VSWR  that  is valued 1.21 at both low frequency and high frequency. The S parameters, basically both cornered spatial and full groundplane pattern produce a better return loss than two others. All four groundplane patterns deliver  equally a mutual coupling parameter.The last, this proposed four element dualband MIMO with various groundplane patterns gives a good farfield properties i.e. gain, radiation pattern, H-E field.
Simple, Easy-use and Low-cost Software for Design of Single and Cascaded Microring Resonators Using Semi-numerical Method Budi Mulyanti; Lilik Hasanah; Tommi Hariyadi; Arjuni B Pantjawati; Heru Yuwono; P. Susthita Menon; Sahbudin Shaari
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 13, No 3: September 2015
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v13i3.1733

Abstract

Development of a simple, easy and low-cost software for designing of waveguide-coupled single and cascaded microring resonator (MRRs) using semi-numerical calculation based on transfer matrix method (TMM), is presented in this paper. The software uses a device model which is embedded on the high index contrast (HIC) structure of silicon-on-insulator (SOI) with monomodal cavity for TE-mode polarizations, operating around 1550 nm optical wavelength. The main aim of the software is to estimate the microring resonator performance parameters, such as free spectral range (FSR) and quality factor (Q-factor). The software is very simple and easy to use. With a standard laptop computer, it only takes few seconds to obtain transmission response, FSR and Q-factor of single MRR for varied waveguides separation distance and ring radius. The results were then verified using simulation method based on finite integration technique using 3D electromagnetic simulator, which need a high memory and processor of computer and take days to execute the simulation. We found only small discrepancy, which in averages are about 4.25% and 10.80% for FSR and Q-factor, respectively. In general, the results obtained from this software are closer to 3D electromagnetic simulation results.