In this paper, a new wideband reconfigurable antenna with beams switching for wireless systems applications is presented and studied. The radiation pattern of the proposed antenna can be changed using the PIN diodes. The designed antenna has a bandwidth of 26.75% from 5.31 to 6.95 GHz and can steer the beam in the azimuth plane. The simulated realized gain of the antenna obtained is 5.9 dB at 5.8 GHz. The proposed antenna can operate for various wireless systems, such as Wi-Fi, WiMAX, Intelligent Transportation System (ITS) and C-band satellite. The simulated results are also presented and investigated.

In this paper, a 3.1–11 GHz ultra-wideband low noise amplifier with low noise figure, high power gain S₂₁, low reverse gain S₁₂, and high linearity using the OMMIC ED02AH process, which employs a 0.18 μm Pseudomorphic High Electron Mobility Transistor is presented. This Low Noise Amplifier (LNA) was designed with the Advanced Design System simulator in distributed matrix architecture. For the low noise amplifier, four stages were used obtaining a good input/output matching. An average power gain S₂₁ of 11.6 dB with a gain ripple of ±0.6 dB and excellent noise figure of 3.55 to 4.25 dB is obtained in required band with a power dissipation of 48 mW under a supply voltage of 2 V. The input compression point 1 dB and third-order input intercept point are −1.5 and 23 dBm respectively. The core layout size is 1.8 × 1.2 mm².

Antennas are essential and crucial components of radar and wireless communication systems, but sometimes their inability to adapt to new operating conditions can hamper system performance. These limitations can be mitigated or eliminated, and reconfigurable antennas can bring new levels of functionality to any system by enabling it to modify its behavior in response to changing system requirements or environmental conditions. Depending on the physical property that makes the antenna reconfigurable, the antennist needs to choose very precise reconfiguration techniques and also the necessary polarization circuits. In accordance with the reconfigurability functions they offer, reconfigurable antennas can be classified into one of four categories: frequency reconfiguration, radiation pattern reconfiguration, polarization reconfiguration and hybrid reconfiguration. This classification will be presented in this chapter, preceded by the principle and main reconfiguration techniques encountered in the literature, as well as the polarization circuits of the active elements required.