Rafiee, Majid (2016) Design And Modeling Of Quasi-Lumped Planar Inverted-F Antenna For Handheld Devices. PhD thesis, Universiti Sains Malaysia.
![[img]](http://eprints.usm.my/style/images/fileicons/application_pdf.png)
|
PDF
- Submitted Version
Download (166kB) | Preview |
Abstract
Teknologi rangkaian tanpa wayar Fourth Generation (4G) telah diperkenalkan rentetan peningkatan permintaan bagi kadar bit tinggi di dalam mobiliti tanpa wayar. Sehubungan itu, reka bentuk yang mengintegrasikan komponen-komponen yang ringan, berkeupayaan tinggi, sedia-ada, serta berkos rendah di dalam terminal kecil seperti telefon bimbit adalah sangat kritikal. Terkini, Planar Inverted-F Antenna (PIFA) digunakan secara meluas sebagai antena utama di dalam terminal kecil ini disebabkan ciri-cirinya yang kecil dan mempunyai nilai Specific Absorption Ratio (SAR) yang baik. Walau bagaimanapun, cabaran utama bagi pereka antena adalah penghasilan antena berstruktur tiga dimensi (3D) untuk difabrikasikan serta dapat digunakan dalam bentuk yang lebih kecil dan mampat. Pada masa ini, kebanyakan telefon bimbit menggunakan Papan Litar Planar, Planar Circuit Board (PCB), sebagai plat bumi menyebabkan komponen-komponen elektrik yang lain menjejaskan keupayaan antena. Tambahan pula, pemasangan PCB ini menyebabkan telefon bimbit tersebut menjadi lebih tebal. Hal ini menyebabkan para pereka antena menggunakan badan telefon bimbit sebagai plat bumi di mana pemasangan ini adalah tidak ideal. Oleh itu, tujuan kajian ini adalah untuk menghasilkan alternatif bagi struktur antena yang memenuhi kriteria-kriteria yang diperlukan terutamanya saiz tanpa menjejaskan ciri-ciri PIFA. Cabaran bagi PIFA konvensional adalah struktur suapannya. Justeru itu, reka bentuk struktur antena dua dimensi (2D) dicadangkan. Reka bentuk ini terdiri daripada elemen separa-tergumpal tunggal CPW dan antena PIFA, dicirikan dengan struktur suapan termudah iaitu jaringan mikrojalur. Struktur antena ini telah disubstrat oleh Duroid RO4003C dengan nilai ketelusan 3.38 dan tebal 0.813 mm manakala saiz bagi resonator adalah 15 x 11mm2 dan ketebalan konduktor adalah 0.035 mm. Reka bentuk dan persamaan radiasi dapat dihasilkan diikuti proses pemodelan, simulasi, fabrikasi dan pengukuran keputusan ini bagi menghasilkan prototaip antena yang berkeupayaan tinggi. Antena ini dioptimumkan untuk beroperasi pada 2.6 Ghz di mana keputusan simulasi dan pengukuran lebar jalur galangan adalah baik iaitu sebanyak 13.65%. Pada frekuensi yang ditetapkan, antena pada satah H menunjukkan corak radiasi ekakutub manakala pada satah E, corak dwikutub diperolehi. Sehubungan itu, antena MIMO telah direka dan difabrikasikan, berdasarkan keupayaan konfigurasi pertama. Bagi tujuan pemodelan, perisian ADS telah digunakan manakala bagi simulasi reka bentuk, perisian Computer Simulation Technology (CST) dan High Frequency Structural Simulator (HFSS) diimplimentasi. Pengukuran lebar jalur mencatatkan sebanyak 10.73% dari elemen pertama dan 12.19% dari elemen kedua. Keputusan simulasi bagi SAR juga berada dalam piawaian yang ditetapkan. Perisian Matlab dan Mathematica digunakan bagi tujuan penandaan nilai parameter struktur antena. Secara keseluruhannya, antena yang dicadangkan mempunyai lebih banyak kelebihan seperti penambahbaikan pengukuran lebar jalur, mudah difabrikasi, berkos rendah serta saiz yang lebih kecil bagi memastikan kepadatannya dengan mempunyai struktur 2D disamping mengekalkan ciri-ciri PIFA iaitu nilai SAR yang rendah. ________________________________________________________________________________________________________________________ Nowadays, increasing demand for having high bit rate in wireless mobility has enabled the introducing Fourth Generation (4G) and beyond technologies. Realizing this fact, conformable, unobtrusive, lightweight, low cost, and ubiquitous equipment, which can be integrated into small terminals such as mobile handsets, are now crucial design considerations. Recently, Planar Inverted-F Antenna (PIFA) is widely used as the main antenna in these small terminals due to its small electrical length and good SAR. However, having a 3D structure is the main challenge for antenna designers to fabricate and use it as a small, compact integrated antenna. Although, in current phones, the main PCB is used as a ground plane, implementing many other electronic devices on the ground plane effect on the antenna performance. In addition, this height,makes the phone thicker. This forces antenna designers to find another ground plane such as phone body (none-ideal). However, this kind of ground plane also suffers by users’ hand. Therefore, the intent of this work is to develop an alternative antenna structure that meets the compact requirements in terms of size, without compromising the PIFA characteristics. Another challenge with the conventional PIFAs is its feeding structure. Therefore, a unique Two Dimensional (2D) antenna design configurations with single and dual CPW-fed quasi-lumped quasi-PIFA antenna is proposed in this work. The design is a simple, single CPW-fed quasi-lumped quasi-PIFA antenna arrangement which was excited by the simplest feeding structure i.e. a microstrip line. The antenna structure was photo-edged on a Duroid RO4003C with a permittivity of 3.38 and thickness of 0.813 mm. The size of the resonator is 15_11mm2 with conductor thickness of 0.035 mm. The design and radiation equations were presented followed by the modeled, simulated, fabricated, and measured results to determine its performance characteristics thereby accrediting the inherent potential of the proposed structure as an antenna. The antenna was optimized to operate in 2.6 GHz, with a good agreement between the simulation results and experimental data over measured 13.65% impedance bandwidth. The antenna demonstrated an omnidirectional radiation pattern in the Hplane and a dipole like pattern in E-plane at desired frequency. A dual elements MIMO antenna was designed, modeled, simulated, fabricated and measured based on the performance of the first configuration. ADS was used for modeling and CST and HFSS were used to simulate the design. The measured bandwidth of 10.73% for first element and 12.19% for the second element were obtained. Also, the simulated result for SAR were in agreement with European Union (EU) and United State (US) standards. Also, Matlab and Mathematica were used for plotting in order to an exact parameter study on proposed structure. Findings indicate that all the experimental results are in good agreement with the modeled and simulated results. The proposed antenna has superior advantages of improved measured bandwidths, easy to fabricate, low cost and most importantly significant small size advantage which ensures its required compactness by having 2D structure while maintaining the advantage of PIFA i.e. having low SAR. Besides the aforementioned advantages, the proposed antenna has significant small size advantage which ensures its required compactness.
| Item Type: | Thesis (PhD) |
|---|---|
| Additional Information: | Full text is available at http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action?institutionalItemId=2800 |
| Subjects: | T Technology T Technology > TK Electrical Engineering. Electronics. Nuclear Engineering > TK7800-8360 Electronics |
| Divisions: | Kampus Kejuruteraan (Engineering Campus) > Pusat Pengajian Kejuruteraaan Elektrik & Elektronik (School of Electrical & Electronic Engineering) > Thesis |
| Depositing User: | Mr Mohd Jasnizam Mohd Salleh |
| Date Deposited: | 12 Jul 2018 08:31 |
| Last Modified: | 15 Aug 2018 03:44 |
| URI: | http://eprints.usm.my/id/eprint/41028 |
Actions (login required)
 |
View Item |
