We report a study of the circular-shaped and rectangular-shaped focus-gate Field Emission Devices (FED) structure.In this work, we have developed a simulator of FED based on the Finite Difference Method (FDM). The major element of this simulator is a modified Fowler-Nordheim (F-N) field emission model. We evaluate the performances of the circular-shaped and rectangular-shaped focus-gate FED structures by using this simulator. Results reveal that the circular-shaped focus-gate FED structure has more collector current. Also, the focusing characteristics of electron beam are improved.

A new method, using genetic algorithms, for constructing a redundant unipolar interconnection weight matrix of the Interpattern Association model is presented. The global searching features of the genetic algorithms are adopted to help us avoiding too complicate procedures to complete a link search of using exhaustive search method. The upper bond and the lower bond of the searching links are adapted from the results of the maximum mode and the minimum mode of the RIPA model respectively. Computer simulation results show that the proposed genetic algorithms method not only has the features of accurate of constructing the IWM, but also has better network performance.