Implementasi bandpass filter m-derived pada pemancar radio FM

Pemancar siaran radio FM adalah salah satu sistem komunikasi nirkabel, bekerja rentang frekuensi 88-108 MHz membutuhkan sebuah filter bandpass untuk menghindari adanya interferensi dengan frekuensi yang berdekatan dengan pemancara radio. Jenis filter yang memiliki performansi cukup baik adalah filter dengan tingkat kecuraman yang cukup tinggi. Namun, untuk mendapatkan tingkat faktor kecuraman yang tinggi dengan menambah beberapa elemen. Maka, pada penelitian ini menambahkan rangkaian m-derived utnuk memberikan respon filter yang lebih curam tanpa menambahkan nilai elemen yang banyak. Tujuan penelitian ini mengetahui perbandingan daya pemancar tanpa filter, dengan bandpass filter, dan menggunakan bandpass filter m-derived. Hasil pengujian daya pancar tanpa filter sebesar 2 Watt, dengan menggunakan bandpass filter daya pancar sebesar 1,05 Watt, sedangkan dengan menggunakan bandpass filter m-derived daya pancar sebesar 1,4 Watt. Kesimpulannya pelemahan (insertion loss) pada Bandpass Filter sebesar 2,53 dB sedangkan pelemahan (insertion loss) pada BPF m-derived section sebesar 1,54 dB dengan menambahkan BPF m-derived section memperbaiki daya keluaran pemancar lebih besar 0,35 W atau 1,01 dB dibandingkan dengan pemancar yang menggunakan BPF tanpa m-derived. FM radio broadcast transmitter is a wireless communication system, with frequency range of 88-108 MHz requires a bandpass filter to avoid interference with frequencies adjacent to radio transmitters. The type of filter that has a fairly good performance is a filter with a fairly high level of steepness. However, to get a high level of steepness factor by adding some elements. So, in this study, we added an m-derived circuit to provide a steeper filter response without adding a lot of element values. The purpose of this study is to compare the transmitter power without a filter, with a bandpass filter, and using an m-derived bandpass filter. The result of testing the unfiltered transmit power is 2 Watt, using a bandpass filter the transmit power is 1.05 Watt, while using the m-derived bandpass filter the transmit power is 1.4 Watt. In conclusion, the insertion loss in the Bandpass Filter is 2.53 dB, while the insertion loss in the BPF m-derived section is 1.54 dB by adding the BPF m-derived section to improve the transmitter output power by 0.35 W or 1 .01 dB compared to transmitters using BPF without m-derived.

Wavelength and throughput tuning of FORR-based optical filter using Sagnac effect

In this paper, analysis of tunable optical filter based on Sagnac effect tuning is presented using a fiber-optic ring resonator (FORR) and the responses of the filters for different FORR and Sagnac loop parameters under steady-state conditions are investigated. Formulation of the optical filter response is presented by considering with/without single and multiple Sagnac loop effects. Effects of the FORR parameters of filter response are studied and analyzed under different parametric conditions for the maximum transmission intensity. The simulation results show that the filter responses are affected strongly by the Sagnac loop and the FORR parameters. With the Sagnac effect, it is shown that full-width at half maximum (FWHM) would increase by increasing the phase difference Δϕ from 0 to 0.20 radian, beyond which it will start decreasing. The difference in FWHM value in this range of Δϕ variations is found to be about 3.77 nm. Between the first and the second resonances at wavelengths 1395 and 1538 nm, the free spectral range (FSR) is found to be 140 nm. In multiple loops effects, by increasing the number of loop turn N, the values of FSR would reduce. For Δϕ = 0.3 and N = 1, 2, 3, the values of FSR are obtained as 144, 74, 47 nm, respectively.

Dielectric-loaded L-band filters for high-power space applications

The design and first experimental results of Tx and Rx L-band bandpass filters for a high-power satellite diplexer are presented in this paper. Designed in the framework of an ESA ARTES AT project, the filters are based on TM010 mode dielectric resonators. These resonators allow for better results in terms of volume occupation with respect to other dielectric resonators still maintaining high Q-factor values (>2000). Volume saving above 30% is achieved with respect to standard coaxial filters. The filter geometries and materials have been chosen in order to improve the power-handling and to cope with related critical issues for space applications (i.e. avoid any multipactor discharge in the operating RF power range and low-PIM response). Measurements of Tx filter show good correlation with the design in terms of central frequency, BW, and unloaded Q-factor (almost 3000). Measurements of Rx filter show a worse correlation with the design in terms of filter response shape. This is ascribed to size tolerances of one of the filter resonators. Multiple analyses are ongoing to remove this degradation in the final engineering model.

Digital Moving Average Filter Application for Echo Signals and Temperature

In this work, we propose a digital filter design, namely moving average filter (MAF) to be implemented on echo signal and temperature data. The echo signal data is obtained from the ultrasonic transducer, while the temperature data is obtained from the PI controller. The implementation of the moving average filter on the echo signal data will compare the second-order MAF and the fourth-order MAF. The results of the test show that the use of a digital filter makes the data smoother when compared to unfiltered data. Furthermore, the comparison of orders on the MAF filter has an impact on the filter response getting closer to the ideal characteristics if using a higher order.

Inter-connected coupled lines Resonator topology for bandpass filter application

This paper presents an inter-connected side-shorted coupled-line resonator topology as a base cell. The base cell is built from two single-shorted quarter-wavelength coupled-line sections, connected in series to give a half-wavelength coupled-line that creates a single resonance of bandpass filter response. Higher-order bandpass filter is produced by adding new single-shorted coupled-line sections, cascaded in an inter-connected manner to the base cell. This new topology creates a unique arrangement that caused cross coupling effects between the resonators, resulting to the occurrence of transmission zeros that lead to the improvement of selectivity of the higher order bandpass filter response. For validation of concept, 2^nd and 3^rd order bandpass filters were fabricated using microstrip technology on Roger 3210 substrate with parameter of <em>Ɛr</em> = 10.2, <em>h</em> = 1.27 mm and <em>tan δ</em> = 3x10-3. The filters were measured and the results show good agreement with simulation results.