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Abstrak :
ABSTRAK
Mengintegrasikan transceiver seluruhnya dalam sebuah chip tunggal merupakan visi masa depan dari sistem nirkabel. Namun demikian, antena dapat dikatakan komponen berukuran terbesar pada sistem ini, sehingga miniaturisasi antena adalah proses yang diperlukan untuk memperoleh rancangan yang optimal. Dan metode yang dipilih untuk miniaturisasi antena adalah dengan pemanfaatan elemen metamaterial Complementary Split-Ring Resonator (CSRR) permitivitas negatif, yang dicetak pada bidang ground antena mikrostrip yang diaplikasikan pada frekuensi kerja 2,6 ? 2,7 GHz. Hasil simulasi menunjukkan ukuran antena dapat direduksi sampai 32% dengan bandwidth (-10dB) sebesar 140 MHz (2,58 ? 2,72 GHz) dan return loss 32,4dB di frekuensi 2,646 GHz. Sedangkan hasil pengukuran mengalami penurunan lebar bandwidth (90MHz) namun masih berada pada frekuensi kerja yang ditentukan. Ini menunjukkan bahwa penempatan elemen metamaterial CSRR pada bidang ground antena mikrostrip dapat memperkecil dimensi antena.

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ABSTRACT
Integrating a transceiver entirely in a single chip is the future vision in wireless system. However, antenna is the largest component in this system, so it makes antenna miniaturization an important thing to do to achieve the optimal design. The chosen method for antenna miniaturization is by using negative permittivity Complementary Split-Ring Resonator (CSRR) metamaterial structure, printed on a ground plane at working frequency 2.6 ? 2.7 GHz. From the simulation, the final design has successfully reduce 32% of the microstrip dimension, which has 140 MHz of bandwidth (-10dB) centered at 2.646 GHz with a return loss of 32.4dB. From the measurement, the antenna has narrower bandwidth (90 MHz), but still inside the working frequency of antenna. This proves that CSRR metamaterial structure placed on the ground plane can make the antenna miniaturization possible.

Abstrak :
ABSTRAK
In this paper a new way of derivation of an evolution equation for short pulses in a dielectric waveguide including one model of a metamaterial waveguide is shown. This derivation model relies upon projecting to an orthogonal basis. In our case such orthogonal basis for cylindrical waveguides is chosen as Bessel functions.

Abstrak :
Perkembangan teknologi komunikasi bergerak menuntut dimensi perangkat yang kecil, tipis, dan ringan. Untuk menjawab tuntutan tersebut, digunakan antena planar. Masalah utama dalam desain antena planar adalah timbulnya gelombang permukaan dalam material substrat yang mengakibatkan penurunan karakteristik radiasi. Salah satu cara mengeleminasi gelombang permukaan adalah penggunaan struktur μ negative (MNG) metamaterial spiral resonator (SR). Oleh karena itu dilakukan studi antena planar struktur spiral resonator (SR) sebagai elemen radiator untuk mencari sifat μ negative (MNG) metamaterial-nya pada rentang frekuensi hingga 5 GHz, mengembangkan model pendekatan analitis untuk mengkarakteristik pola radiasi, melakukan simulasi dan pengukuran karakteristik radiasi pada frekuensi 2,4 GHz. Hasil studi antena planar struktur MNG metamaterial SR menunjukkan bahwa permeabilitas efektif (μeff) mempunyai bagian riil negatif ?2,5 pada frekuensi paling rendah 0,1 GHz, relatif tidak berubah terhadap perubahan nilai N = 3, 5, 7, dan 10. Bagian imajiner negatif menunjukkan kecenderungan frekuensi bergeser ke kiri dengan bertambah besarnya nilai N. Sedangkan nilai permitivitas efektif (eff) positif untuk semua rentang frekuensi, kecuali rentang frekuensi 0,1 ? 0,7 GHz berharga negatif. Hal ini menunjukkan bahwa nilai negatif μeff dan nilai positif eff merupakan sifat MNG struktur SR pada rentang frekuensi tersebut. Perbandingan hasil simulasi dan perhitungan permeabilitas efektif (μeff) dan permitivitas efektif (eff) menunjukkan kemiripan karakteristik. Selain melalui simulasi dan pengukuran, karakteristik pola radiasi diperoleh melalui pendekatan linier susun (linear array approach) untuk struktur SR patch tunggal dan pendekatan planar susun (planar array approach) untuk struktur SR patch susun. Perbandingan karakteristik pola radiasi hasil simulasi, pengukuran, dan pendekatan linier susun atau pendekatan planar susun menunjukkan kesamaan pada arah boresight, meskipun terjadi sedikit perbedaan pada sidelobe dan backlobe. Dengan demikian model pendekatan analitis ini dapat digunakan sebagai metode alternatif untuk mengkarakteristik pola radiasi antena planar struktur MNG metamaterial SR. Hasil simulasi dan pengukuran karakteristik radiasi antena yang distudi menunjukkan kemiripan dengan perolehan frekuensi 2,41 GH, S11 = ?23 dB, bandwidth hingga 96 MHz pada S11 = ?10 dB, gain antena = 6,8 dB dan efisiensi hingga 73,4%. Dimensi antena yang diusulkan berkurang hingga 53 % dibanding dengan antena patch konvensional. Spiral Resonator (SR) mempunyai struktur yang unik, dapat berfungsi sebagai radiator dan secara signifikan dapat mereduksi dimensi antena planar. Oleh karena itu, struktur SR memiliki prospek yang baik untuk pengembangan aplikasi antena planar.

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The development of mobile communications technology requires the device to be small, thin, and light weight. To solve this requirement, the planar antenna is used. The main problem in the design of planar antenna is the emergence of surface waves in the substrate material that reduce the radiation characteristics. To eleminate the surface wave, the μ negative (MNG) metamaterial spiral resonator (SR) is used. Therefore, the study of planar antenna with SR structure as a radiator elemen is conducted to search its μ negative (MNG) metamaterial at the frequency range up to 5 GHz, to develop a model of the analytical approach for characterizing a radiation pattern, to simulate and measure radiation characteristics at the frequency of 2.4 GHz. The result of the study of the planar antenna with μ negative (MNG) metamaterial SR structure shows that effective permeability value has a negative real part of ?2.5 along the frequency at least 0.1 GHz, which is relatively change to the N value such as N = 3, 5, 7, and 10. Its imaginary part shows the frequency tend to move left if N value increase. The effective permittivity is positive for the frequency range of 0 ? 5 GHz, except for the frequency range of 0.1 ? 0.7 GHz is a negative. It shows that the negative value of μeff and positive value of eff indicate the MNG properties of the SR structure at the frequency range. Comparison between simulation and calculation results of the effective permeability and permittivity shows a good agreement. In addition through simulation and measurement, the radiation pattern can be characterized by linear array approach for single patch SR structure and planar array approach for patch array SR structure. Comparison among of the simulation, measurement, and linear array approach for single patch SR structure and planar array approach for patch array SR structure shows a good agreement at a boresight direction, even though there was a slight difference at the sidelobe and backlobe. It shows that this analytical model can be used as alternative method to characterize the radiation pattern of the planar antenna with μ negative (MNG) metamaterial SR structure. The simulation and measurement results of the radiation characteristic of the proposed antenna show a good agreement such as the frequency of 2.41 GHz, S11 = ?23 dB, bandwidth up to 96 MHz at S11 = ?10 dB, antenna gain = 6.8 dB and efficiency up to 73.4%. Spiral resonator (SR) has a unique structure, it can be functionalized as a radiator and significantly reduce the dimension of the planar antenna. Therefore, the SR structure has a good prospect for developing of the planar antenna aplication.

Abstrak :
Antenna can be one of the largest components in a wireless device; therefore antenna miniaturization can reduce the overall size of wireless devices. One method used to reduce the element size of an antenna is by using metamaterial structures. This paper discusses a Left-Handed Metamaterial (LHM) structure stacked on a two-element microstrip antennas array for miniaturization and gain enhancement at a frequency of 2.35 GHz. To observe the impact of the LHM structure on the antenna, first this paper discuss the design of a conventional rectangular shape microstrip antenna without a LHM structure, then a design of the LHM structure which shows both negative permittivity and negative permeability. This LHM structure is then implemented on a conventional single element microstrip antenna and on a two-element microstrip antennas array. Results and discussion of implementation of the LHM structure on the conventional microstrip antenna is provided in this paper. The results show that good agreement between simulated and measured results has been achieved. The simulation results show that the antenna works at a frequency of 2.29?2.42 GHz with a bandwidth of 128 MHz (5.4%) and a gain of 8.2 dBi, while the measurements show that the antenna works at a frequency of 2.26?2.41 GHz with a bandwidth of 146 MHz (6.21%) and a gain of 8.97 dBi. In addition, by comparing the substrate dimension for the two element array antennas, with and without the LHM structure, shows a 39% reduction is achieved.

Abstrak :
Antenna can be one of the largest components in a wireless device; therefore antenna miniaturization can reduce the overall size of wireless devices. One method used to reduce the element size of an antenna is by using meta material structures. This paper discusses a Left-Handed Meta material (LHM) structure stacked on a two-element microstrip antennas array for miniaturization and gain enhancement at a frequency of 2.35 GHz. To observe the impact of the LHM structure on the antenna, first this paper discuss the design of a conventional rectangular shape microstrip antenna without a LHM structure, then a design of the LHM structure which shows both negative permittivity and negative permeability. This LHM structure is then implemented on a conventional single element microstrip antenna and on a two-element microstrip antennas array. Results and discussion of implementation of the LHM structure on the conventional microstrip antenna is provided in this paper. The results show that good agreement between simulated and measured results has been achieved. The simulation results show that the antenna works at a frequency of 2.29–2.42 GHz with a bandwidth of 128 MHz (5.4%) and a gain of 8.2 dBi, while the measurements show that the antenna works at a frequency of 2.26–2.41 GHz with a bandwidth of 146 MHz (6.21%) and a gain of 8.97 dBi. In addition, by comparing the substrate dimension for the two element array antennas, with and without the LHM structure, shows a 39% reduction is achieved.

Abstrak :
Semakin berkembangnya aplikasi penggunaan data AIS (Automatic Identification System) baik untuk pelacakan kapal, pemantauan lalu lintas laut, maupun untuk pengawasan maritime; membuat AIS mulai diaplikasikan pada satelit untuk mendapatkan coverage area yang lebih besar sehingga bisa melengkapi data AIS terestrial. Indonesia melalui Lembaga Penerbangan dan Antariksa Nasional (LAPAN), sudah mempunyai dua buah satelit mikro yang membawa misi AIS yaitu LAPANA2/ ORARI dan LAPAN-A3/IPB. Dan dalam rencana pembangunan satelitnya, LAPAN juga akan membuat satelit mikro lainnya yang juga membawa AIS sehingga pada akhirnya bisa mendapatkan data kapal di seluruh wilayah Indonesia secara near realtime. AIS menggunakan frekuensi VHF (161.975 MHz untuk AIS Class A dan 162.025 MHz untuk AIS Class B), sehingga dimensi antena yang digunakan besar. Hal ini akan menjadi permasalahan ketika satelit yang digunakan berplatform mikro, sehingga diperlukan miniaturisasi terhadap antena penerima AIS pada satelit. Permasalahan lain yang terjadi pada AIS berbasis satelit adalah adanya data collitions pada daerah yang mempunyai traffik padat. Pada tesis ini diusulkan sebuah antena yang dirancang sebagai antena penerima AIS untuk satelit mikro pada frekuensi 161.975 MHZ (AIS Class A) – 162.025 MHz (AIS Class B) yang memiliki dimensi cukup kecil dengan gain yang cukup tinggi. Teknik miniaturisasi yang digunakan adalah dengan mengunakan antena mikrostrip tipe meander dengan menambahkan bentuk metamaterial untuk meningkatkan performasinya. Hasil simulasi menunjukkan antena VHF berukuran 133.00 x 88.00 x 1.52 mm3 dengan gain 1.663dB. Antena yang dirancang memiliki polarisasi linier dan pola radiasi omnidirectional dengan beamwidth pada H-plane 88.5°. Hasil pengukuran menunjukkan frekuensi operasi pada 156.98-163.18 MHz dengan gain 0.18 dB. Dengan demikian antena ini dapat digunakan untuk menerima seluruh data AIS kelas A, data AIS kelas B dengan gain -9dB, serta VDES (VHF Data Exchange System). Miniaturisasi dengan teknik meander-line dan struktur metamaterial ini berhasil mereduksi dimensi sebesar 42%. Antena fabrikasi mempunyai pola radiasi omnidirectional dengan beamwidth pada E-plane 338.6° dan H-plane 88.26° sehingga ketika antena VHF ini diletakkan pada satelit, proyeksi antena pada permukaan bumi berkurang 50% dari sebelumnya sehingga dapat digunakan untuk mengurangi data coalition pada satelit. ......The development of AIS (Automatic Identification System) data usage applications, for tracking vessels, monitoring sea traffic, and for maritime surveillance; encourage AIS begin to be applied in satellites to get a larger coverage area so that it can complement terrestrial AIS data. Indonesia, through National Institute of Aeronautics and Space (LAPAN), already has two micro satellites that carry the AIS mission, namely LAPAN-A2/LAPAN-ORARI and LAPAN-A3/LAPAN-IPB. And in its satellite development plan, LAPAN will also create other micro satellites that also carry AIS so that in the end they can get near real-time ship data throughout Indonesia. AIS uses VHF frequencies (161,975 MHz for AIS Class A and 162,025 MHz for AIS Class B), so the dimensions of the antenna used are large. This will be a problem when the satellite is used on a micro platform, so it is necessary to miniaturize the AIS receiver antenna on the satellite. Another problem that occurs in satellite-based AIS is the presence of coaillition data in areas that have dense traffic. In this thesis, we propose an antenna designed as an AIS receiver antenna for micro satellites at a frequency of 161,975 MHz (AIS Class A) - 162,025 MHz (AIS Class B) which has a fairly small dimension with a high enough gain. The miniaturization technique used is to use a meander-type microstrip antenna by adding a metamaterial shape to improve its performance. The simulation results show that the VHF antenna measures 133.00 x 88.00 x 1.52 mm3 with a gain 1.663dB. The antenna is designed to have linear polarization, and an omnidirectional radiation pattern with a beamwidth on the H plane of 88.5 °. The measurement results show the operating frequency at 156.98-163.18 MHz with gain 0.18 dB. Therefore this antenna can be used to receive all AIS class A data, class B AIS data with a gain of -9dB, and VDES (VHF Data Exchange System). Miniaturization using the meander-line technique and the metamaterial structure was successful in reducing dimensions by 42%. Fabricated antenna also has an omnidirectional radiation pattern with a beamwidth in the E-plane 338.6° and the H-plane 88.26°. And when this VHF antenna is placed on a satellite, the antenna projection on the earth's surface is reduced by 50% from the previous one so that it can be used to reduce coalition data on the satellite.