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"Telekomunikasi selalu mengalami perkembangan yang pesat, baik dari sisi teknologi maupun jumlah penggunanya. Namun hal ini juga diikuti dengan permintaan kapasitas yang terus meningkat, sementara spectrum frekuensi yang tersedia juga terbatas. Untuk mengatasi masalah tersebut, smart antenna dengan menggunakan sistem beamforming mulai dikembangkan. Secara mendasar, terdapat dua tipe dari sistem smart antenna, yaitu switched beam dan adaptive array. Sistem switch beam telah banyak dikembangkan karena dalam impelementasinya sederhana dan lebih ekonomis dibandingkan sistem adaptive array. Tidak seperti sistem adaptive array, sistem switch beam hanya terdiri dari beberapa elemen peradiasi, jaringan pembentuk beam, dan RF switch sementara sistem adaptive array membutuhkan operasi dan pemrosesan sinyal yang lebih rumit.Fokus skripsi ini adalah pada perancangan algoritma untuk sistem pengendali beamforming. Microcontroller diprogram untuk mengendalikan rangkaian switching yang terhubung pada antena susun yang terintegrasi dengan rangkaian butler matriks. Sistem pengendali bekerja dengan melakukan komparasi tegangan analog yang diterima oleh antena terhadap tegangan threshold.Hasil pemrograman menunjukkan bahwa microcontroller sudah dapat melakukan penghitungan tegangan threshold secara otomatis dan melakukan komparasi nilai input dengan nilai threshold. Hasil keluaran dari microcontroller tersebut berupa nilai digital dengan keluaran sebanyak 4 port sehingga terdapat 15 kombinasi. Hasil algoritma diuji dengan proses integrasi menggunakan antena butler matriks beserta elemen-elemen pendukung ke rangkaian switching.

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Telecommunication is always experiencing fast development, both in terms of technology also the number of users. However, it is also followed by increasing of capacity demand, but the available frequency spectrum is also limited. To resolve these problems, a smart antenna that using beamforming system has developed. Smart antenna system has two types, there are switched beam and adaptive array. Beam switch system has been developed because simpler in its implementation and more economical than the adaptive array system. Unlike the adaptive array systems, beam switch system consists of some radiating elements, beamforming network, and RF switches while adaptive array system requires components and signal processing which more complicated.

This research is focusing on the design of algorithms for the beamforming control system. Microcontroller is programmed to control the switching circuit which connected to the antenna array is integrated with the butler matrix circuit. Control systems will compare the analog voltage received by the antenna to the threshold voltage.

The result of programming is shown that the microcontroller is able to calculate the threshold voltage automatically and comparate the input value with the threshold value. The output of the microcontroller is a digital value with 4 ports output so there are 15 combinations. The result of algorithm is tested by integration process using matrix butler antenna and switching circuit supporting elements."

"Teknik beamforming digunakan untuk mengetahui letak suatu objek melalui penyaringan frekuensi sinyal yang dipancarkan objek tersebut. Suatu sistem beamforming dapat terdiri dari antena mikrostrip, rangkaian butler matriks, serta rangkaian switching yang berfungsi untuk mengatur daya yang masuk ke rangkaian antena butler matriks.Fokus skripsi ini adalah pada rancang bangun rangkaian switching berbentuk SP4T (Single Pole Four Throw) pada frekuensi 2,35 GHz. Perancangan dimulai dari pembuatan rangkaian switching SPDT (Single Pole Double Throw), parameterisasi komponen yang berpengaruh pada rangkaian SPDT, dan membuat rangkaian SP4T yang memiliki komponen sama serta struktur mirip dengan rangkaian SPDT. Parameterisasi telah dilakukan pada komponen pasif kapasitor dan induktor, serta panjang dan lebar rangkaian. Perancangan simulasi rangkaian SP4T memakai komponen dengan nilai yang terdapat pada pasaran, serta penyesuaian nilai komponen dengan hasil parameterisasi. Di sini performa yang menjadi pertimbangan adalah return loss serta insertion loss rangkaian.Hasil parameterisasi memberikan informasi bahwa performa rangkaian semakin baik saat nilai kapasitansi serta panjang rangkaian diturunkan, dan nilai induktansi dinaikkan. Hasil simulasi rangkaian switching SP4T akhir memberikan nilai S11 (return loss) sebesar -21,138 dB, nilai S12 dan S15 sebesar -7,179 dB, serta nilai S13 dan S14 sebesar -7,374 dB. Nilai isolation between port mempunyai nilai antara (-18,277 dB) ? (-6,262 dB).Hasil pengukuran rangkaian switching SP4T menunjukkan nilai S11 sebesar -13,48 dB. Nilai return loss ini menunjukkan kondisi yang cukup matching karena nilainya yang lebih kecil daripada -10 dB. Sementara itu nilai S12, S13, S14, dan S15, berturut-turut sebesar -8,097 dB, -11,403 dB, -5,936 dB, dan -8,537 dB. Isolation between port mempunyai nilai antara (-27,1 dB) ? (-21,3 dB).Rangkaian switching SP4T menunjukkan perbedaan level daya output ketika rangkaian diberi maupun tidak diberi tegangan DC. Ketika rangkaian diberikan tegangan DC, maka daya output akan menurun. Ini menunjukkan bahwa rangkaian dalam kondisi tidak aktif. Sementara saat rangkaian dalam kondisi aktif, maka tidak ada tegangan DC yang diberikan pada rangkaian. Selisih daya output dari kondisi on-off rangkaian bervariasi antara 3,56 - 6,18 dB.

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Beamforming techniques are used to determine the location of an object through filtering the frequency of signal emitted by the object. A beamforming system can consist of microstrip antenna, butler matrix circuit and switching circuit which has a function to adjust the power into the butler matrix antenna circuit.

The focus of this skripsi is to design an SP4T (Single Pole Four Throw) switching circuit at 2.35 GHz frequency. The design starts from designing SPDT (Single Pole Double Throw) switching circuit, parameterization of components which affect the SPDT circuit, and designing a SP4T that has the same components and similar structures to SPDT circuit. The parameterization was conducted on passive components capacitors and inductor, as well as the length and the width of the circuit. The design of the circuit SP4T use components with the value that exist in the market, as well as the adjustment of the value of the component with the results of parameterization. Here the consideration performances are the return loss and insertion loss of the circuit.

Parameterization results provide information that the performances of the circuit show better result when the capacitance value and the length of the circuit are lowered, and the inductance value is increased. The final SP4T switching circuit simulation results have the S11 (return loss) value of -21,138 dB, the S12 and the S15 value of -7,179 dB, the S13 and the S14 value of -7,374 dB. The isolation between port has the values between (-18,277 dB) ? (-6,262 dB).

The SP4T switching circuit measurement results have the S11 value of -13,48 dB. The return loss value shows adequate matching condition because it is smaller than -10 dB. Meanwhile the S12, S13, S14, and S15 values are -8,097 dB, -11,403 dB, -5,936 dB, and -8,537 dB, respectively. The isolation between port have the values between (-27,1 dB) ? (-21,3 dB).

The SP4T switching circuit shows the different levels of output power when the circuit is supplied or not supplied by a DC voltage. When the circuit is supplied by a DC voltage, therefore the output power is decreased. This indicates that the circuit is not active. Meanwhile when the circuit is active, therefore no DC voltage supplied to the circuit. The range of output power difference from the on-off circuit condition varies between 3,56 - 6,18 dB."

"Adaptive array atau adaptive beamforming adalah peningkatan dari teknik antenna yang menawarkan performa optimal dan memberikan keuntungan luar biasa untuk aplikasi bergerak. Sistem ini dipadukan dengan sistem diversitas MIMO space time block coding (STBC) serta sistem adaptive modulation and coding (AMC) untuk memperoleh keuntungan tersebut. Unjuk kerja sistem ditunjukkan melalui simulasi dengan MATLAB dan pengujian lapangan dengan parameter kualitas yakni ber, rssi, cinr dan throughput. Sistem diujikan dengan beberapa kondisi yang berhubungan dengan banyaknya user, jarak, modulasi dan coderate. Hasil dari pengujian tersebut menunjukkan sistem Adaptive beamforming sangat tahan terhadap lingkungan multipath, memiliki pengelolaan effisiensi ruang yang baik serta peningkatan kualitas sinyal melalui penolakan interferensi, effisiensi power, dan penguatan sinyal.

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Optimum performance and absollutely, make more advantage for mobile application. This system be combined with MIMO space time block coding (STBC) diversity scheme and adaptive modulation coding (AMC) scheme to achieve this advantages. System performance is shown through simulation and trial test with quality parameter such as ber, rssi, cinr and throughput.

System is tested through several condition that related number of users, distance, modulation dan coderate. The result of test shown Adaptive beamforming scheme have higher robustness toward multipath environtment, have efficient managerial for space and improvement signal quality through anticipating interference, power efficiency, and signal amplication."

"Skripsi ini membahas rancang bangun antena reconfigurable untuk aplikasi cognitive radio pada alokasi spektrum 1,8 GHz, 2,1 GHz uplink, 2,1 GHz downlink, dan 2,35 GHz. Rancang bangun antena terdiri dari dua antena yaitu antena sensing dan antena communicating yang digabungkan dalam satu divais. Antena sensing memiliki karakteristik ultrawideband dari 1,65 GHz - 3,75 GHz (bandwidth = 2,1 GHz) dan antena communicating memiliki karakteristik narrowband pada frekuensi 1.8 GHz, 2.1 GHz uplink, 2.1 GHz downlink, dan 2.35 GHz. Hasil validasi dengan pengukuran diperoleh hasil yang sesuai dengan rancangan simulasi, terutama meliputi parameter return loss, pola radiasi, dan gain.

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This bachelor thesis discusses a design and fabrication of reconfigurable antenna for cognitive radio applications, especially for allocation of spectrum 1.8 GHz, 2.1 GHz Uplink, 2.1 GHz Downlink, and 2.35 GHz. The antenna design consists of two antennas which sensing antenna and communicating antenna. The sensing antenna has ultrawideband characteristics from 1.65 GHz - 3.75 GHz (the bandwidth about 2.1 GHz) and the communicating antenna has narrowband characteristics at the center frequency 1.8 GHz, 2.1 GHz uplink, 2.1 GHz downlink, and 2.35 GHz. The validation has been conducted by the measurement, where it agrees with the simulation result, in particular for the parameter of return loss, radiation pattern and gain of the antenna."

"Like the previous editions, Antenna Theory, Third Edition is designed to meet the needs of electrical engineering and physics students at the senior undergraduate and beginning graduate levels, and those of practicing engineers as well. The text assumes that the readers have a knowledge of basic undergraduate electromagnetic theory, including Maxwell's equations and the wave equation, introductory physics, and differential and integral calculus."

""Stutzman's 3rd edition of Antenna Theory and Design provides a more pedagogical approach with a greater emphasis on computational methods. New features include additional modern material to make the text more exciting and relevant to practicing engineers; new chapters on systems, low-profile elements and base station antennas; organizational changes to improve understanding; more details to selected important topics such as microstrip antennas and arrays; and expanded measurements topic"--"