mohammadmahdi taskhiri

This paper presents an inhomogeneous lens to radiate a control-table Fan Shaped pattern for long-range automotive applications. Fan Shaped pattern of the designed lens covers more angles in azimuth. The proposed circular aperture inhomogeneous lens is designed based on the critical angle theorem. The profile of the dielectric constant of the proposed lens changes in 3 directions of ρ, φ, and z. The lens is matched to the source and surroundings. A closed-form formula is offered for an arbitrary fan-shaped pattern lens antenna. A compact circular lens with a diameter of 20 mm and thickness of 2.25 mm is simulated in CST full-wave software to validate the design structure.

In this paper, a 3.1 to 10.6 GHz low noise amplifier has been designed using 130 nm CMOS technology. In this circuit, the source degeneration technique is employed to increase the bandwidth and achieve input impedance matching as well. In addition, a current reuse technique is employed to achieve a high gain. Since most output impedance matching techniques degrade gain or linearity, an inverter along with an inductive peaking technique is used to provide output impedance matching of 50 ohms and to improve both linearity and gain. This technique enhances the third harmonic behavior and increases the gain by 2.7 dB. The proposed circuit achieves S11 of less than - 9.1dB, S22 of less than -10 dB, the maximum gain of 19.7 dB, NF of 2 to 2.7 dB, and IIP3 of -3.5 dBm. Moreover, the power consumption of the proposed circuit is 28 mw and the core layout size is 991.84 μm×701.4 μm. The advantages of the proposed circuit over UWB structures with the same technology are higher gain, lower Noise Figure, and better output matching.

This article presents a phased array antenna employing MEMS phase shifter. The proposed phased array antenna consists of eight square patch antennas operating at 10.4 GHz with a bandwidth of 400 MHz. Feed line for each patch passes through a MEMS phase shifter realized by a series of bridges above the transmission line. The distance between the bridge and the transmission line underneath it is adjusted using a control signal applied to them, which in turn, introduces a loading effect on the feed signal. This changes the effective length of the feed line and provides phase shifts with 15-degree resolution. Low loss conversion units are employed in order to couple the phase shifter and microstrip lines. The integrated numerical analysis approach applied to phased array antenna employing MEMS phase shifter and the scattering parameters and radiation patterns at different steering angles demonstrate the effectiveness of employing MEMS phase shifters in designing phased array antennas. The proposed design methodology might be applied to other frequency bands, such as millimeter-wave for automotive applications. Employment of MEMS phase shifters instead of solid-state ones provides high linearity, high power handling, and wide frequency range of operation.