#Gaussian filter matlab 2009 software#
#Gaussian filter matlab 2009 free#

Moreover, the filter shape can be tailored if the modulated electrical waveform is well designed 31, 32, 33, 34, 35. The filter bandwidth is reconfigurable by broadening the Brillouin pump with different modulation schemes 29, 30. The filter selectivity can be further increased by using phase modulated probe 25 or double sideband cancellation 26, 27, 28. The filter tunability is easily realized by modulating a single tone signal at different frequency 22, 23 or by using a second laser source 24. Thanks to the narrow SBS linewidth, the SBS-based MPFs have a very high discrimination resolution 17.

Several SBS-based MPFs have been reported since a decade ago. SBS effect can be considered as an active optical filter in terms of signal selection. Meanwhile, in order to enhance functionality and robustness and reduce cost, size and power consumption, there has been a consistent effort towards the integration of microwave photonic devices 18, 19, 20, 21.

The other category is using optical filter techniques to filter the RF-modulated optical signal directly by micro-ring resonators 14, fibre Bragg grating 15, liquid crystal arrays 16 and stimulated Brillouin scattering (SBS) 17. Several works have been reported to retain a single passband including employing an optical filter 7 and broadening the tap width 13.

#Gaussian filter matlab 2009 free#

This method provides certain flexibility but due to the inherent nature of the discrete FIR filter, the frequency response has multiple harmonic passbands, which restricts the filtering within one free spectral range (FSR). The dispersive media can be a dispersive fibre 11 or a chirped fibre Bragg grating (CFBG) 12. The optical carriers can be multiple laser diodes 8, a broadband optical source 6, an optical comb 7, 9 or a multi-mode mode lock laser 10. Then the RF-modulated carriers pass through dispersive media to obtain different time delay and are combined together to convert to RF signal. Each carrier acts as a filter tap and the tap coefficients are usually set by amplitude and phase manipulation with liquid crystal based technique 6, 7. For this method, the RF signal is first modulated on several optical carriers at different wavelengths. One is delayed-tap based finite impulse response (FIR) filter. The realization of the MPF can be roughly categorized into two approaches.

By using MPFs instead of conventional electrical filters, the RF system flexibility can be increased dramatically. As a key MWP component, the microwave photonic filter (MPF) has been studied intensively and has shown its prominent superiority in terms of tunability and reconfigurability 4, 5. In radio frequency (RF) systems, the microwave photonics (MWP) has been attracting persistent attentions since it provides potential possibilities to overcome some inherent limitations of electronics 1, 2, 3. Nanosecond pulse shaping by implementing precisely defined filters is demonstrated to prove the filter superiority and practicability. The unprecedented multi-dimensional filter flexibility offers new possibilities to process microwave signals directly in optical domain with high precision thus enhancing the MPF functionality.

#Gaussian filter matlab 2009 software#

For the first time the filter shape, bandwidth and central frequency can all be precisely defined by software with ~MHz resolution. Here we present a polarization-insensitive single-passband arbitrary-shaped MPF with ~GHz bandwidth based on stimulated Brillouin scattering (SBS) in optical fibre. Thus the MPF application is basically limited to signal selection. Although filter reconfigurability and tunability have been demonstrated repeatedly, it is still difficult to control the filter shape with very high precision. Microwave photonic filters (MPFs) are of great interest in radio frequency systems since they provide prominent flexibility on microwave signal processing.