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Abstrak :
Beragam aplikasi komunikasi gelombang mikro, mendorong inovasi perangkat transceiver yang mampu bekerja dalam beragam aplikasi secara bersamaan (concurrent). Frekuensi kerja yang saling berdekatan sehingga memungkinkan terjadinya interferensi. Untuk menekan terjadinya interferensi, dibutuhkan filter sebagai penekan frekuensi yang tidak diinginkan dan melewatkan frekuensi yang diinginkan. Teknologi stepped impedance resonator (SIR) dalam bandpass filter (BPF) multiband memiliki jarak minimal antar frekuensi kerja yang ditentukan oleh rasio impedansi (K). Tri-section stepped impedance resonator (3 SSIR) merupakan pengembangan dari SIR yang dapat menghasilkan concurrent multiband BPF. Tetapi frekuensi kerja berikutnya dipengaruhi oleh frekuensi kerja sebelumnya, sehingga tidak dapat menghasilkan bandwidth simetri. Pada penelitian ini dirancang quadband BPF Hairpin 3 SSIR dengan penambahan open stub, sehingga mampu menghasilkan empat passband dan meningkatkan selektivitas BPF. Dengan pengaturan jarak resonator dan memperhitungkan jarak minimal antar frekuensi kerja, sehingga mengurangi pengaruh frekuensi kerja sebelumnya dan terbentuk bandwidth simetri 10 MHz yang diharapkan pada keempat passband. Dari microstrip line dan 3 SSIR diperoleh hasil perhitungan, kemudian dilakukan optimasi pada simulasi untuk mendapatkan frekuensi tengah yang diharapkan pada keempat passband. Hasil simulasi memperlihatkan quadband BPF Hairpin 3 SSIR dapat bekerja pada frekuensi tengah 905 MHz, 1805 MHz, 2605 MHz dan 3305 MHz secara bersamaan. Dengan parameter S11 dan S22 < -10 dB, S21 >-3 dB, VSWR ≤ 2, group delay <10 nS. Namun bandwidth -3 dB belum simetri pada keempat passband. Hasil pengukuran memperlihatkan parameter S21 tidak mendapatkan hasil yang diharapkan pada frekuensi kerja pertama dan keempat. Parameter S11, S22, VSWR, dan group delay telah memenuhi kriteria perancangan, namun terjadi pergeseran frekuensi tengah. ......Multiple microwave communications applications, encourage innovation transceiver device are able to operate in variety of applications simultaneously (concurrent). Operating frequencies that are close together to allow interference. To suppress interference, required filter as a suppressor of unwanted frequency and pass desired frequency. SIR technology in the BPF has a minimum distance between operating frequencies is determined by the impedance ratio (K). 3 SSIR is a development of the SIR is capable of generating concurrent multiband BPF. But the frequency of subsequent work is influenced by the frequency of the previous work, so can not produce symmetric bandwidth. In this research is designed quadband BPF Hairpin 3 SSIR with the addition of the open stub so as to produce four BPF passband and increase selectivity. The resonator spacing and calculate the minimum distance between the operating frequencies, thereby reducing the effect of frequency of previous operate and formed 10 MHz bandwidth symmmetry is expected in the fourth passband. Of the microstrip line and 3 SSIR obtained calculation result, then do optimization in the simulation to obtain the expected center frequency in the fourth passband. The simulation shows quadband BPF Hairpin 3 SSIR can operate at the center frequency 905 MHz, 1805 MHz, 2605 MHz and 3305 MHz simultaneously. With parameter S11 and S22 < -10 dB, S21 >-3 dB, VSWR ≤ 2, delay's group < 10 nS. But bandwidth -3 dB haven't symmetry on passband fourth. Measurement result show parameter S21 haven't gotten expected result on first and fourth operating frequency. Parameter S11, S22, VSWR, and delay's group has met the criteria for design, but the shift in the center frequencies.

Abstrak :
The book discusses active devices and circuits for microwave communications. It begins with the basics of device physics and then explores the design of microwave communication systems including analysis and the implementation of different circuits. In addition to classic topics in microwave active devices, such as p-i-n diodes, Schottky diodes, step recovery diodes, BJT, HBT, MESFET, HFET, and various microwave circuits like switch, phase shifter, attenuator, detector, amplifier, multiplier and mixer, the book also covers modern areas such as Class-F power amplifiers, direct frequency modulators, linearizers, and equalizers. Most of the examples are based on practical devices available in commercial markets and the circuits presented are operational. The book uses analytical methods to derive values of circuit components without the need for any circuit design tools, in order to explain the theory of the circuits. All the given analytical expressions are also cross verified using commercially available microwave circuit design tools, and each chapter includes relevant diagrams and solved problems. It is intended for scholars in the field of electronics and communication engineering.