Dyg Norkhairunnisa Abang Zaidel

Design of compact single-section directional coupler for butler matrix beam-forming MIMO

This paper demonstrates a new design of 3 dB coupler operating in UWB frequency band between 3.1 GHz and 10.6 GHz. Together with UWB phase shifter, this coupler is claimed to be one of the key factors in designing a Butler Matrix that can operate in very wide frequency range. Butler Matrix has been seen to be the most preferable technique to realize the beam-forming network besides provide compact in size and more cost-effective. The arrangement between beam-forming and multiple-input and multiple-output (MIMO) can broaden the coverage and capacity of users for wireless communication system. The proposed coupler design was accomplished in multilayer microstrip-slot technology by employing broadside coupling technique. The initial dimension of the coupler was obtained using a simple mathematical formula and finalized using CST Microwave Studio simulator. The simulation results show the coupler is having a very tight coupling of 3 dB ± 2 dB, the return loss and isolation are better than 21 dB and the phase difference performance is in the range of 90° ± 2° over the designated band. The designed device occupies an area of 25 mm × 15 mm.

An improved design of wideband Wilkinson power divider with stubs for wireless communication application

An improved design of wideband Wilkinson power divider with stubs concerning operating frequency of 2 to 7 GHz is presented in this paper. Power divider is designed by adding stubs at transmission line of Port 1, 2 and 3, which the position of stubs is studied for wideband application. CST Microwave Studio is used to design the proposed power divider and perform its parametric analysis. From the simulation results, the return loss is observed to be better by 1 dB and the bandwidth is 25% wider compared to the conventional Wilkinson power divider design.

The design of ultra wideband six-port network by using ground-slotted technique

A new design of compact ultra wideband (UWB) six-port network by using ground-slotted technique is presented in this paper. The proposed six-port network is accomplished by constructing four in-phase two-section power dividers and two 90o power dividers by using CST Microwave Studio 2010. The presented result shows that the proposed UWB six-port network offers good amplitude and phase characteristic performances for frequency range of 3.1 to 10.6 GHz.