Investigation of a Tunable Microwave Photonic Filter Based on an Acetylene Reference Cell

Introduction.Recently, the development of tunable microwave photonic filters has attracted great scientific and practical interest. Such microwave photonic filters are a good alternative to traditional electrical solutions, due to low losses, wide operating frequency range and such filters can be easily integrated into various telecommunication systems. By using an acetylene reference cell and a laser with tunable wavelength can make it possible to create tunable microwave photonic filter with wide operating frequency range.Aim.Investigation of the characteristic of a tunable microwave photonic filter based on an acetylene reference cell, as well as research possible solution to reduce losses in filter bandwidth; numerical simulation of microwave photonic filter characteristics.Materials and methods.Experimental study was carried out on an experimental prototype of a tunable microwave photonic filter. The filter consisted of a laser with a tunable wavelength, a phase modulator, an acetylene reference cell, an optical fiber connecting the gas cell with a photodetector, and a photodetector. Theoretical study was carried out by modeling of the transmission characteristics of the microwave photonic filter.Results.Experimental transmission characteristics of a tunable microwave photonic filter were obtained. The tuning of the filter bandwidth by tuning laser wavelength was studied. Modeling of transmission characteristics of microwave photonic filter was performed. Possible solution to reduce losses in filter bandwidth was proposed.Conclusion.A tunable microwave photonic filter based on an acetylene reference cell is proposed. Losses in the filter bandwidth was about −30 dB. Using high-power laser and a photodetector with a high photocurrent can reduce losses in the filter bandwidth.