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"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."

"Penelitian ini mengkaji pengaruh doping Lithium (Li) dan Titanium (Ti) pada BiFeO3 (BFO). Semua sampel disintesis menggunakan metode sol-gel. Tahap selanjutnya adalah dengan melakukan komposit senyawa BFO yang di doping Lithium dan Titanium dengan poliuretan (PU) dan karbon (C). Difraksi sinar-X, SEM/EDS, dan vector network analyzer (VNA) dilakukan untuk mengkarakterisasi struktur mikro dan sifat elektromagnetik dari sampel yang disiapkan. Pengujian Bi1−xLixFeO3 (x = 0.02, 0.04, 0.06) menunjukkan nilai permeabilitas tertinggi diperoleh pada konsentrasi x = 0.06 yang juga dihasilkan puncak serapan tertinggi dengan reflection loss (RL) sebesar -46 dB pada frekuensi10.08 GHz dengan bandwidth (BW) 0.1 GHz. Hasil pengujian BiFe1-yTiyO3 (y = 0, 0.01, 0.03, 0.05, 0.07) diperoleh nilai permitivitas tertinggi pada komposisi y=0.03, yang juga dihasilkan penyerapan gelombang mikro tertinggi dengan RL sebesar -35 dB pada frekuensi 11.12 GHz dengan BW 0.46 GHz. Bahan komposit PU/C/BLFO6 menghasilkan RL sebesar -23.32 dB pada frekuensi 10.76 GHz dengan BW 0.59 GHz, sedangkan pada bahan komposit PU/C/BFTO3 menghasilkan RL sebesar -42.21 dB pada frekuensi 10.48 GHz dengan BW 0.83 GHz. Bahan komposit dengan komposisi berat BLFO6 (60%) dan BFTO3 (40%) [PU/C/BLFTO64] dengan ketebalan sampel 2 mm menghasilkan serapan tertinggi dibandingkan dengan komposisi bahan komposit lainnya dengan RL −50.56 dB pada frekuensi 10.68 GHz dengan BW 0.78 GHz. Penambahan doping Li dan Ti pada BFO terbukti dapat meningkatkan sifat permeabilitas dan permitivitas yang merupakan salah satu persyaratan agar BFO dapat dijadikan bahan penyerap gelombang mikro yang baik. Penambahan PU/C juga terbukti dapat meningkatkan serapan gelombang mikro dan memperlebar bandwidth. Bahan komposit PU/C/BLFTO64 mempunyai sifat penyerap gelombang mikro yang baik pada frekuensi X-band.

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This study investigates the effect of Lithium (Li) and Titanium (Ti) doping on BiFeO3 (BFO). All samples were synthesized using the sol-gel method. The next step is to perform a composite of Lithium and Titanium doped BFO compounds with polyurethane (PU) and carbon (C). The X-ray diffraction, SEM/EDS, and vector network analyzer (VNA) were conducted to characterize the microstructure and electromagnetic properties of the as-prepared samples. The test result of Bi1−xLixFeO3 (x = 0.02, 0.04, 0.06) showed the highest permeability values and also produces the highest reflection loss (RL) of −46 dB over a 0.1 GHz bandwidth at 10.08 GHz. The test results of the BiFe1-yTiyO3 (y = 0.01, 0.03, 0.05, 0.07) obtained the highest permittivity value at the doping of y = 0.03 and also was produces the highest microwave absorption with RL −35 dB over a 0.41 GHz bandwidth at 11.12 GHz. The composite material of PU/C/BLFO6 produced an RL of −23.32 dB over a 0.59 GHz bandwidth at 10.76 GHz, while the composite material of PU/C/BFTO3 produced an RL of −42.21 dB over a 0.83 GHz bandwidth at 10.48 GHz. A composite material with BLFO6 (60%) and BFTO3 (40%) [PU/C/BLFTO64] weight fractions and a sample thickness of 2 mm produced the highest absorption compared to other compositions with RL −50.56 dB over a 0.78 GHz bandwidth at 10.68 GHz. The doping of Li and Ti to BFO is proven to improve the permeability and permittivity properties which are one of the requirements for BFO to be used as a good microwave absorbent material. The addition of PU/C is also proven to increase microwave absorption and widen bandwidth. The results indicate that the composite material of PU/C/BLFTO64 were successfully gained and the as-prepared samples possess excellent microwave absorption properties in X-band frequency."

"ABSTRAKBand Pass Filter (BPF) memiliki peran penting dalam banyak aplikasi RadioFrekuensi (RF). BPF digunakan untuk memisahkan frekuensi yang berbeda. Hal inidisebabkan Spektrum elektromagnetik merupakan sumberdaya terbatas sehinggaharus dibagi. BPF digunakan untuk memilih sinyal RF dalam frekuensi kerjanya.Berbagai aplikasi komunikasi nirkabel terus muncul dan mengharapkan kinerja filterRF dengan kinerja yang tinggi dan ukuran yang lebih kecil. Proyek ini mempelajariprinsip mikro-strip bandpass RF filter. Metode yang digunakan Tangga dan Hairpin.Jenis Chebysev dengan orde 5 dan ripple sebesar 0,01 dB. Sistem ini disimulasikandalam software Desain Advanced System (ADS), kemudian di pabrikasi dan diukuruntuk memvalidasi desain. Tujuan penelitian ini adalah untuk merancang Microstripfilter bandpass untuk Automatic Dependent Surveilance Broadcast (ADS-B)dengan Frekuensi Pusat 1090 MHz menggunakan Ladder dan Metode Hairpin dankemudian membandingkan kedua metode untuk memperoleh kinerja yang lebihtinggi dan ukuran yang lebih kecil.

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ABSTRACTBand Pass Filters has an important role in many Radio Frequency (RF) applications.They are used to separate different frequencies. The electromagnetic spectrum islimited and has to be shared; filters are used to select the RF signals within assignedspectral limits. Emerging applications such as wireless communications continue tochallenge RF filters with ever more stringent requirements—higher performance andsmaller size. This project studied the principle of micro-strip RF bandpass filter. Themethod used the Ladder and Hairpin. The Chebysev type with order 5 and ripple of0.01 dB was used. The system is simulated in software Advanced Design System(ADS), fabricated and measured for validate the design. The objectives are todesign Micro-strip bandpass filter for Automatic Dependent Surveilance Broadcast(ADS-B) with Frequency Center 1090 MHz using Ladder and Hairpin Method andthen compare the both methods for obtain higher performance and smaller size."