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Abstract-This paper aims to develop interactive media in the form of application of Applied Electromagnetics learning, based on Augmented Reality (AR) technology. This application is developed to visualize a point and vector in 3 dimensional coordinate system (3D) using marker and camera of Android smartphone/tablet. The system is able to visualize Cartesian coordinates, cylindrical coordinates, and spherical coordinates, points, and vectors into 3D form with optimal distance of 10--40 cm. Questionnaire results obtain MOS value of 4.31. This result suggests that learning integrated with AR technology can help improve understanding and stimulate students' motivation in exploring learning subject Applied Electromagnetics, especially the coordinate system. Intisari-Makalah ini bertujuan mengembangkan media interaktif berupa aplikasi pembelajaran ElektromagnetikaTerapan berbasis teknologi Augmented Reality (AR). Aplikasi ini dikembangkan untuk memvisualisasikan sebuah titik dan vektor dalam sistem koordinat 3 dimensi (3D) dengan menggunakan marker dan kamera ponsel pintar/tablet Android. Aplikasi dapat memvisualisasikan koordinat Cartesian, koordinat silindris, dan koordinat bola, titik, dan vektor ke dalam bentuk 3D dengan jarak optimal pengambilan gambar marker sepanjang 10--40 cm. Hasil pengujian, menggunakan kuesioner yang diisi oleh pengguna aplikasi dan diukur dengan metode MOS, memberikan nilai 4,31. Nilai ini menunjukkan bahwa pembelajaran yang diintegrasikan dengan teknologi AR dapat membantu meningkatkan pemahaman dan menstimulasi motivasi mahasiswa dalam mengeksplorasi pembelajaran mata kuliah Elektromagnetika Terapan, khususnya materi sistem koordinat.

Abstrak -Pada sistem Synthetic Aperture Radar (SAR), lebar pita menentukan resolusi yang diinginkan. Jika lebar pita sempit, maka resolusi yang didapatkan akan tinggi sehingga objek yang diamati akan lebih presisi. Untuk mendapatkan performa tersebut, dibutuhkan filter yang dapat menjaga lebar pita dari keluaran generator sinyal Chirp. Penelitian ini merancang filter dengan selektivitas tinggi pada frekuensi 1,27 GHz dengan lebar pita sebesar 10 MHz. Dengan karakteristik tersebut, perancangan filter dapat menggunakan resonator berbentuk kotak karena dapat menghasilkan lebar pita yang sempit. Dari hasil perancangan menggunakan duroid 5880 dengan permitivitas relative sebesar 2,2 didapatkan respon frekuensi pada 1,27 GHz dengan nilai S11 sebesar -36,25 dB dan nilai S21 sebesar -0,92 dB. Untuk lebar pita pada rentang frekuensi 1,265 -1,275 GHz didapatkan nilai S11 dan S21 secara berurutan sebesar -14,37 dB dan -1,09 dB serta -14,43 dB dan -1,08 dB. Abstract -In the Synthetic Aperture Radar (SAR) system, the bandwidth specifies the desired resolution. If the bandwidth is small, then the resolution obtained will be high so that the observed object will be more precise. To obtain such performance, a filter that can stabilize the bandwidth from Chirp Generator output is required. This study designs a filter with high selectivity at a 1.27 GHz frequency with a 10 MHz bandwidth. With these characteristics, a rectangular resonator filter design can be used because it can produce narrow bandwidth. The designed filter using Duroid 5880 with relative permittivity 2.2 obtains the frequency response at 1,27 GHz with value of S11 equal to -36,25 dB and S21 value equal to -0,92 dB. For bandwidth at the frequency range 1,265 -1,275 GHz, it is obtained the values of S11 and S21 respectively -14.37 dB and -1.09 dB also -14.43 dB and -1.08 dB.

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At present, the need for internet access in public area using wireless connections is increasing drastically and this should be supported by good network infrastructure. Wireless network is one of the best alternative in building a practical internet network. WDS is a system to develop wireless internet network without having to use cable as its backbone for access point but instead utilize wireless path from its access point. The problems that often arise in the design of wireless LAN network is the poor signal received by the user due to the installation of an access point that is poor location-wise. This is because at some point it is very difficult to install Access point using cable because the distance is too far from the existing router. In this paper, we propose to use three scenario of WDS mode to compare its performance. We investigate three different topology policy models of the WDS Bridge point-to-point, WDS Bridge point to multipoint and WDS repeater. The use of these three topologies aims to reach locations that are not covered by wireless LAN network, in addition this method can save the use of network resources such as LAN cables. Based on the simulation results, it is found that the topology point to point gives better value but it generated higher delays. The delay generated on point to point is higher than other topologies. Meanwhile, the measurement results are not much different on topology point to multipoint with repeater topology. The point to multipoint topology is slightly better than the repeater of the three QoS parameters.