A novel approach to ULTRA-WIDEBAND (UWB) antenna design is presented which is based on a general description for the geometry of monopole antennas. This general description is capable of producing almost all possible shapes for monopole antennas and it is compatible with different optimization methods. The general description is used for the optimization of rotationally-symmetric monopole antenna with finite ground plane. The optimization of antennas is performed by applying a hybrid procedure, which begins with a global search and completes with a local optimization. The optimization procedure aims at minimizing the reflection from antennas while reducing the distortion of radiated pulses. In some cases, the reduction of variations in the energy pattern is also considered. The numerical results show the reliability and effectiveness of the whole process and considerable improvement in comparison with similar antennas reported in the literature.

In this paper, an ULTRA-WIDEBAND metamaterial absorber is designed and simulated. The proposed absorber is planar and low profile. It is made of a copper sheet coated with two dielectric layers. Each unit cell of the metamaterial structure is composed of multiple metallic split rings, which are patterned on the top and middle boundaries of the dielectrics. The designed absorber utilizes different resonances of the split rings with non-identical parameters. In order to achieve ULTRA-WIDEBAND absorption, dimensions of the rings are designed to represent dissimilar nearby resonant frequencies. An ULTRA-wide bandwidth of 67% for 85% absorption is achieved. The absorber’ s performance is investigated for TE and TM polarizations, and with varying incidence and polarization angles. ULTRA-wide band performance of the structure for the case of normal incidence changes to multi-band absorption, with increasing the incidence angle. Electric field distribution of the rings for three low, middle and high frequencies in the absorption bandwidth is simulated and graphically demonstrated. The field distribution verifies that the rings with larger dimensions interact more effectively with low frequency electromagnetic waves, and the rings with smaller dimensions have stronger effects on high frequency waves.

This work proposes an objective function to optimize an ULTRA WIDEBAND antenna for adjusting the bandwidth and coupling with other elements, based on the performance comparison of several objective functions from the literature. The optimal dimensions of a printed rectangular monopole antenna were obtained with the Particle Swarm Optimization method to compare such functions. In the results of the comparison, the linear functions had a mean value of S11 magnitude near the threshold, but they presented a smaller standard deviation than the rest of the functions. The logarithmic and cubic functions showed a mean value of S11 magnitude higher than the double of the threshold, but they had superior standard deviation values, which did not happen with the quadratic function. Hence, the proposed function is the mean of a logarithmic expression with the quadratic argument. With this function, a bandwidth adjustment of 130%, a mean S11 magnitude of -22.1 dB and a standard deviation equal to 6.7 dB were obtained on the resonant band for the designed antenna. In this way, the proposed function can be used to avoid interference with other wireless systems and to obtain a uniform coupling of the antenna.

In this paper, a Distributed Amplifier (DA) by using HEMT technology for ULTRA-WIDEBAND application is presented.Creation of Distributed integrated circuit has been investigated for approximately seventy years rapidly to developing semiconductor process technologies in the modern IC design. By using of this method, multiple parallel signals are combined and obtain to increase the bandwidth, enhanced power combining amplitude, and novel design capabilities for IC process. The circuit was designed and simulated in ED02AH technology by using ADS2010. The 4-stage design achieves 15.5 dB of power gain (± 0.5 dB) from 3.1 to 10.6 GHz. Reflected power of the input and output from loads matched to 50 Ohm are all below -10 dB over the bandwidth of the device, as is power transmitted from the output to the input. The device is stable for a wide range of input and output loads.

The Low Noise Amplifier (LNA) stands as a crucial element RF receiver chain, demanding a delicate interplay of characteristics such as high gain, low noise figure (NF), superior linearity, and an extensive dynamic range. De-signing an ULTRAWIDEBAND (UWB) LNA poses a complex challenge as engineers grapple with intricate trade-offs inherent in these parameters. To address these challenges, noise cancellation techniques have emerged as valuable tools, revolutionizing the design of UWB LNAs by relaxing the traditional trade-off between bandwidth and input matching. This innovative approach not only enhances bandwidth but also effectively cancels out the un-desirable noise and nonlinearities from the input MOSFET. Despite the advancements afforded by noise cancellation, the broad bandwidth of UWB LNAs presents a significant hurdle. If the linearity is insufficient, the UWB LNA faces performance degradation due to increase in-band interference. In response, this article proposes an inventive linearization technique, a combination of Noise Cancelling (NC) and complementary derivative super-position (CDS), aiming to increase the linearity of UWB LNAs. Through meticulous simulations conducted using Cadence Virtuoso with GPDK090 library, the proposed LNA showcases impressive performance metrics across the UWB spectrum. Notably, it achieves a gain ranging from 12.5 dB to 15.5 dB, a noise figure within the range of 3.9 dB to 5.26 dB, and an IIP3 spanning from 6.3 dBm to 8.8 dBm. Remarkably, this innovative LNA accomplishes these feats while operating with a modest power consumption of 11.36 mW from a 1.2 V supply. This groundbreaking technique holds promise for significantly enhancing the efficiency and overall performance of UWB LNAs within contemporary RF receiver systems.