Multiband hairpin-line bandpass filters by using metamaterial complimentary split ring resonator

Telecommunication systems for the new generation have greatly stimulated the demand for multi-band bandpass filters with compact dimensions, low insertion loss, robust, low cost and less complex design. In this paper, a compact multi-band bandpass filter, with the fractional bandwidth of 40% and 20% at resonant frequency 3.5 and 5.5 GHz respectively with the response of Chebyshev passband ripple of 0.1 dB is presented. This bandpass filter is suitable for WiMAX application. The design is based on the hairpin-line configuration and metamaterial of complementary split ring resonator structure. The hairpin-line is used for the compact structure design and easy to fabricate because it has open-circuited ends that require no grounding. While the complementary split ring resonator structure is easy to design and can provide multi-band without affecting of size and performance of the filter. The simulated results show the dual-band bandpass response with the insertion loss is 0 dB and high attenuation at stopband. The proposed filter provides a compact, low insertion loss, and less complex structure design that are promising candidates in order to meet the demands of the new generation of communication systems

Design of Miniaturized Multiband Patch Antenna Using CSRR for WLAN/WiMAX Applications

A novel miniaturized multiband, single-feed microstrip patch antenna is presented in this paper for WLAN and WiMAX applications. Both size reduction and multiband are obtained by etching the Multiple Complementary Split Ring Resonators (MC-SRR) on the ground plane of the normal patch antenna. At first, the normal patch antenna produces a single band of 5.15 GHz; 200 MHz (5.0500~5.2499). Subsequently, a Single Circular Split Ring Resonator (SC-SRR) is etched on the ground plane and produces a triple band of: 3.25 GHz; 288 MHz (3.1085~3.3964), 4.5 GHz; 101.3 MHz (4.4488~4.5501), and 5.22 GHz; 220 MHz (5.1191~5.3400) and Double Single Circular Split Ring Resonator (DC-MCSRR) with: 2.99 GHz; 60.7 MHz (2.9574~3.0181), 3.57 GHz; 324.7 MHz (3.4065~3.7312), and 5.1413 GHz; 115.4 MHz (5.0817~5.1971). The working bandwidths cover the desired frequency bands of WLAN 5.2 GHz and WiMAX 3.3/3.5 GHz. The proposed (MC-SRR) antenna can be employed to wireless communication systems due to its simplicity in design, compactness and miniaturization

Miniturize flexible RFID antenna design using metamaterial structure

Radio Frequency Identification (RFID) is the application of electromagnetic fields to identify and track tags that attached on the objects. It transmits or reads the radio frequency waves in the system. However, due to rapid development of technology in telecommunication, a much more smaller and flexible device is needed. Therefore, in this paper, a new design of flexible RFID antenna using metamaterial structure has been proposed. At first, the basic rectangular microstrip patch antenna with resonant frequency of 900MHz is designed. Then, the CSRR metamaterial structure is introduced at the ground plane to reduce the size of the antenna while the polydimethylsiloxane (PDMS) material is being use as the antenna substrate for flexibility. All the simulation designs were done using CST software. The antenna performances such as resonant frequency, return loss, radiation pattern, gain and bandwidth are then be analyzed and presented. The results show good performances and can be applied for future application

Sintesis dan pencirian getah asli cecair terhidrogen untuk adunan polimer

Sistem hidrazin hidrat/hidrogen peroksida (HH/H2O2) digunakan untuk menjana sumber hidrogen bagi tujuan penghidrogenan getah asli cecair (LNR) melalui penghasilan diimida. Spesies diimida yang terhasil akan membekalkan sumber hidrogen kepada ikatan karbon ganda dua dalam rantai polimer LNR. Getah asli cecair terhidrogen (HLNR) yang terhasil menunjukkan ciri lebih tahan suhu berbanding LNR. Suhu degradasi HLNR didapati meningkat pada 435°C berbanding LNR iaitu pada 381°C. HLNR seterusnya dijadikan pengserasi dalam penghasilan adunan polimer polistirena/getah asli, PS/NR/HLNR (60/35/5). Kekuatan regangan dan impak PS/NR masing-masing meningkat sebanyak 70.7% dan 149.6% setelah HLNR ditambah sebagai pengserasi dalam adunan. Beberapa pemerhatian morfologi melalui mikroskop optik dan SEM turut menyokong kesan penyerasian adunan PS/NR dengan HLNR

Adsorption of Cu2+ Ions using Rubber-Based Hydrogel

Hydrogels are one of the most powerful adsorbents for removing heavy metal ions among all adsorbents. However, most of today's hydrogels are synthetic polymers with high costs, non-environmentally friendly, and have low stability. Therefore, in this study, natural rubber (NR) was used as the basic material for hydrogels due to its high mechanical properties, plasticity or viscosity, elasticity, and tensile strength. This study is focusing on the Cu adsorption method using a rubber-based hydrogel that is prepared with a combination of acrylic acid (AA) and methylenebisacrylamide (MBA). The rubber-based hydrogel was immersed in the synthetic Cu wastewater, and the percentage removal was calculated. Cu initial concentration, contact time, and rotation speed were the three independent variables used for optimization using Response Surface Methodology (RSM). With an initial Cu concentration of 47.66 mg/L, a contact time of 10 hours, and a rotation speed of 91.32 rpm, RSM optimization shows that the best conditions for Cu removal are 72.19%. The SEM-EDX micrograph of the hydrogel before adsorption shows numerous pores, but after adsorption it is smoother and has fewer holes. This study will contribute to the development of a new method to remove Cu from wastewater

A Novel Right Handed Circular Polarization Folded Reflectarray Antenna at 60 GHz

A novel right-handed circular polarization (RHCP) folded reflectarray antenna with optimized parameters is presented at 60GHz. The RHCP folded reflectarray antenna is designed using left handed circularly polarized selective surface (LHCPSS) Pierrot unit cell. Through simulation, it is shown that the antenna operates well at 60GHz. The maximum antenna directivity is 19dB with a reflection coefficient below -15dB. The radiation patterns showed good responses with side lobes level below -10dB. In addition, the best axial ratio at 60GHz is achieved as 0.75dB

Circular polarization folded reflectarray antenna for 5G applications

Fifth-generation (5G) is a wireless connection built specifically to keep up with the rapid increase of devices that need a mobile internet connection. A system working on 5G band can provide higher bandwidth and faster data rate as compared to fourth-generation (4G) band. Thus, an antenna with higher gain and lower profile is required to support this system. On the other hand, the performance of circular polarization antenna is better than linear polarization antenna due to its ability to accept wave from different direction. In this project, a low profile circular polarization folded reflectarray antenna with operating frequency of 28 GHz is presented. This project is divided into two parts. In the first part, a linear polarization folded reflectarray antenna is designed. In this second part, a meander lines polarizer is used to convert the linear polarization antenna to circular polarization antenna. The antenna is fed by a linear polarized waveguide. Each radiating element of the antenna is in rectangular shape. The size of the radiating elements are selected according to obtain required phase delay to form a planar phase front in the far-field distance. Both of the antennas are simulated by using Computer Simulation Technology (CST) software. Finally, the results shows excellent performances with 16.81dB directivity and 1.49dB axial ratio at 28GHz. Thus, the antenna is very suitable for 5G applications

Pengoptimuman parameter untuk penurunan diimida getah asli cecair dalam sistem hidrazin hidrat/hidrogen peroksida menggunakan kaedah rangsangan permukaan (RSM)

Getah asli cecair (LNR) dihasilkan daripada proses penyahpolimeran getah asli yang menghasilkan rantaian polimer lebih pendek dan berat molekular kurang daripada 105. Namun, LNR masih mempamerkan tahap degradasi dan ketahanan termal yang rendah seperti getah asli, disebabkan oleh kehadiran ikatan karbon ganda dua pada rantaian polimer. Dalam kajian ini, penurunan diimida menggunakan pengoksidaan hidrazin hidrat dengan hidrogen peroksida dijalankan untuk menghidrogenkan unit tidak tepu LNR. LNR terhidrogen (HLNR) dicirikan menggunakan spektrometer infra-merah (FTIR) dan spektrometer resonans magnetik nuklear (NMR). Pengoptimuman parameter tindak balas dilakukan dengan memanipulasi parameter masa dan suhu tindak balas berdasarkan kaedah rangsangan permukaan (RSM) dengan 5-aras-2-faktor reka bentuk komposit putaran tengah (CCRD). Satu model kuadratik yang signifikan telah dihasilkan untuk menghubungkan dua parameter tersebut dengan nilai R2 adalah 0.9986, menunjukkan bahawa model yang terhasil adalah sangat sepadan dengan data uji kaji. Keputusan kajian menunjukkan bahawa peratus penghidrogenan boleh ditingkatkan sehingga 91.2%. Seterusnya, berdasarkan RSM, parameter yang optimum bagi penurunan diimida LNR ini didapati pada suhu 55.9oC selama 6.7 jam, menghasilkan 80.2% HLNR. Kajian ini telah menunjukkan reka bentuk uji kaji secara statistik yang novel bagi menghidrogenkan LNR. Pelbagai variasi peratus penghidrogenan produk HLNR dalam kajian ini menyumbang kepada lebih banyak aplikasi produk yang memerlukan peratusan ketepuan unit yang tertentu

Compact patch MIMO antenna with low mutual coupling for WLAN applications

A compact triband microstrip patch MIMO antenna is proposed for WLAN applications. The antenna consists of two patches antenna elements, which are orthogonally placed to each other for high isolation at 2.4, 2.8 and 5.8 GHz frequency bands. On its ground plane, a Complementary Split Ring Resonators (CSRRs) is etched for size reduction and multiband generation. The proposed compact MIMO antenna covers an entire size of 58 x 45 x 1.6 mm3, with the patch size of 13.3 x 17.1 mm2. A 79% size reduction at 2.45 GHz was achieved for miniaturization, with a very low mutual coupling (S21 and S12) of -32 dB at all bands