Analysis of tunable photonic microwave bandpass filter with negative coefficient

Shiraz University of Technology, Modarres Boulevard, P.O. Box 71557-13876, , Modarres Boulevard, P.O. Box 71557-13876, Shiraz, Iran

Corresponding author: ^* salehi@sutech.ac.ir

Received: 29 October 2008
Revised: 8 September 2009
Accepted: 7 June 2010
Published online: 22 July 2010

Abstract

Analysis of tunable photonic microwave bandpass filter with negative coefficient based on an electro-optic phase modulator (EOPM) followed by a fiber Michelson interferometer with orthogonally polarized arms is presented. The Michelson interferometer is made by connecting two fibers to the output ports of a polarization beamsplitter (PBS) and attaching high reflecting Bragg gratings at the other end of the fibers. The negative coefficient is generated from the optical interference of the two phase modulated optical carriers when recombined at the PBS. A two-tap microwave bandpass filter with one negative coefficient is presented. The chromatic dispersion is expected to have no effect on this filter. The filter is tunable over a wide frequency bandwidth using short fiber lengths.