The miniaturization of the patch antenna has become an important issue in reducing the volume of entire communication system. This paper presents an improved method of size reduction of a microstrip antenna using the genetic algorithm. The shape of a typical rectangular patch is modified in order to reduce it resonance frequency keeping the physical volume of the antenna constant. Indeed, the initial patch is divided into 10 × 10 small uniform rectangles (Pixel), and the genetic algorithm searches, the optimal configuration for the desired goal. The resonance frequency of a micro-strip patch is shifted from 4.9 GHz to 2.16 GHz and a rate of miniaturization is up to 82%. To validate the procedure, an antenna prototype has been fabricated and tested with an FR4 substrate. The measurements results were in good agreement with simulation ones.

In this paper an IGZO-TFT based on High-K gate dielectric is simulated using TCAD software. We report on the electrical properties of amorphous indium-gallium-zinc-oxide thin-film transistors (TFTs) with a range of oxides (SiO ₂ , HfO ₂ , ZrO ₂ , Al ₂ O ₃ or TiO ₂ ) gate dielectrics materials IGZO-TFT with TiO ₂ layer dielectric exhibited threshold voltage V _th of 2 V, a Saturation mobility μ _sat of 4.51 cm ² /Vs, Subthreshold swing SS of 0.075 V/dec, and a current ratio I _on /I _off of 1.244E13. These characteristics make it suitable for use as a switching transistor in low-power application, furthermore a temperature-dependent transfer characteristic of the a-IGZO TFT, ranging from 300 to 500 k. show that more the dielectric constant of the oxide gate dielectric is high, more we get a high current.

Neural networks are been used for the last years for modeling the nonlinear microwave devices as the Pseudomorphic High Electron Mobility Transistor (pHEMT). In this paper the neuro-space mapping (SMNN) technique is used for modeling the DC characteristic of pHEMT, in this approach the Angelov model is used as the coarse model, which can be adjusted using the fine model based on measurement. Good results are obtained for the drain-current, the trans-conductance and for the output conductance.

This This paper presents a low noise amplifier (LNA) for WLAN applications. The target frequency band 802.11b/g@ 2.4GHz. The amplifier is characterized by input and output reflection coefficients less than -15dB, a forward gain (S21) of 15.112dB, a noise figure of 0.37dB and the third input intercept point of 14.8dB.