Analysis of signal impairment and crosstalk penalty induced by different types of optical filters in 100 Gbps PM-DQPSK based systems

Optical filters are crucial elements in optical communication networks. Their influence toward the optical signal will affect the communication quality seriously. In this paper we will study and simulate the optical signal impairment and crosstalk penalty caused by different kinds of filters, which include Butterworth, Bessel, Fiber Bragg Grating (FBG) and Fabry-Perot (F-P). Signal impairment from filter concatenation effect and crosstalk penalty from out-band and in-band are analyzed from Q-penalty, eye opening penalty (EOP) and optical spectrum. The simulation results show that signal impairment and crosstalk penalty induced by the Butterworth filter is the minimum among these four types of filters. Signal impairment caused by filter concatenation effect shows that when center frequency of all filters is aligned perfectly with the laser's frequency, 12 50-GHz Butterworth filters can be cascaded, with 1-dB EOP. This value is reduced to 9 when the center frequency is misaligned with 5 GHz. In the 50-GHz channel spacing DWDM networks, total Q-penalty induced by a pair of Butterworth filters based demultiplexer and multiplexer is lower than 0.5 dB when the filter bandwidth is in the range of 42-46 GHz.

Improving the pass-band return loss in liquid crystal dual-mode bandpass filters by microstrip patch reshaping

In this paper, the design and experimental characterization of a tunable microstrip bandpass filter based on liquid crystal technology are presented. A reshaped microstrip dual-mode filter structure has been used in order to improve the device performance. Specifically, the aim is to increase the pass-band return loss of the filter by narrowing the filter bandwidth. Simulations confirm the improvement of using this new structure, achieving a pass-band return loss increase of 1.5 dB at least. Because of the anisotropic properties of LC molecules, a filter central frequency shift from 4.688 GHz to 5.045 GHz, which means a relative tuning range of 7.3%, is measured when an external AC voltage from 0 Vrms to 15 Vrms is applied to the device.

Livestock feedlot runoff control by vegetative filters /

Mode of access: Internet.

Rock filters for removal of algae from lagoon effluents /

Mode of access: Internet.

Gabor Peterdi, twenty-five years of his prints, 1934-1959.

Mode of access: Internet.

Removal of free-living nematodes by rapid sand filters /

Vita.

Non-destructive measurement of U-235 retained in absolute air filters /

"April 15, 1964."

Removal of radioactive iodine by laboratory trickling filters /

Mode of access: Internet.

How do I manage my used oil and used oil filters?

"Information presented in this publication is intended to provide a general understanding of the statutory and regulatory requirements governing used oil and oil filters generated by small businesses remediation waste. This information is not intended to replace, limit or expand upon the complete statutory and regulatory requirements found in the Illinois Environmental Protection Act and Title 35 of the Illinois Administrative Code of Regulations."

Identification of sources causing TSP non-attainment in the Peoria area : analysis of historical high-volume filters /

"Project no. 10.064."

Operator's, organizational, direct support, and general support maintenance manual : test set, noise loading, AN/GSM-161A (including filters).

"September 1972."