Implementation Of Antenna Arrays Research Articles

Innovation Design of High Gain Array Antenna for 5G Communication

The fifth-generation (5G) wireless communication system requires high gain antennas to support the growing demand for high-speed data transmission and low-latency connectivity. High gain antennas are crucial for enhancing the signal strength and extending the coverage area of 5G networks. By using multiple antenna elements, an array can achieve higher gain and directivity compared to a single element antenna. This improvement in gain enables better signal reception and transmission, leading to increased communication range, higher data rates, and improved reliability. In this paper, we discuss the design and implementation of antenna arrays for improving antenna gain in 5G communication systems at 3.5 GHz.The design of the array antenna incorporates single, dual, quad, and octal element structures to enhance the antenna's gain. The proposed antenna has been examined, and the results indicate that it has a return loss of -37.4 dB at the resonant frequency of 3.5 GHz, an antenna gain of 7.22 dB, and a bandwidth of 286.5 MHz. The use of a single, dual, quad, and octal element array configuration is anticipated to improve the gain performance of the antenna, making it a promising option for 5G communication systems.

Efficient waveguide power combiners at mm‐wave frequencies

AbstractIn this study, an efficient power combiner for mm‐wave frequency transmitters is investigated. The combiner is based on a parallel plate waveguide (PPW) excited with multiple parallel feeds. The Doherty power combiner scheme is also integrated in the proposed concept, to increase the efficiency of the amplifiers when implementing amplitude modulation. The advantage of the proposed PPW combiner with respect to other concepts, for example, the ones based on substrate‐integrated waveguide, is the wider bandwidth and the scalability to an arbitrary number of inputs. Measured results from a demonstrator realised in standard printed circuit board technology are presented. Two variations of the combiner are implemented, one terminated with a 50 Ω coaxial output, and another integrated with an antenna. In the latter case, the waveguide is folded so that both the power combiner and the antenna fit within a half wavelength size, and thus would be compatible with a dense antenna array implementation.

MMSE algorithm based two stages hybrid precoding for millimeter wave massive MIMO systems

Millimeter wave (mm-wave) communications has been sighted as solution becoming strong technology for the fifth generation networks. That is because, it brings orders of degree higher spectrum than current cellular bands and helps applications that require weak latency. Massive MIMO is used to minimize the severe constraints enjoined by the excessive propagation loss for millimeter wave frequencies. Where, normal implementation of antenna arrays is transmitted to multiple users simultaneously. Due to hardware constraints in mm-wave systems, classical lower frequency precoding techniques are difficult to be applied at mm-wave. A proposed modified hybrid precoding is suggested for downlink massive MIMO mm-wave systems in this paper. The hybrid precoding consists of mixed of analog and digital processing which is based on minimum mean square error (MMSE) algorithm. Where, quantized beamstearing codebooks are used to produce the analog and digital beamforming vectors with small training and feedback overhead. Extensive simulation programs are executed to compare the performance of the proposed precoding scheme with analog beamforming performance at different digital baseband precoders such as zero forcing precoder. Moreover, studies on the impact of modified hybrid beamforming parameters on the system performance are done. These parameters such as; the number of BS antennas, the number of mobile station antennas, number of effective channel quantization bits and number of RF beamforming quantization bits. Besides, the impact of rate threshold on the coverage probability is studied under different values of NBS antennas. It is shown that the performance of the modified hybrid precoding using MMSE is very close to the single user performance with only 0.5 b/s/Hz performance degradation at SNR = − 5 dB.

Single-RF Multi-Antenna Transmission With Peak Power Constraint

Electronically steerable parasitic array radiator (ESPAR) technology enables the implementation of antenna arrays of a number of elements with a single radio frequency (RF) source. Two approaches to achieve stable transmission using an ESPAR antenna (EA) are to increase the self-resistance of an EA or to transmit signals closely approximating the actual signals that keep the EA stable. Both approaches did not take into account the impact of limited power on an EA transmission, which is a practical constraint on power amplifier design. We propose a new transmission scheme to enable an EA to provide stable multiple antenna functionality taking into account the instantaneous total power requirement. This problem is formulated as a non-convex optimization problem and it is solved analytically by coordinate transformation and geometric analysis. The optimal approximate signals are obtained using root finding and interior-point algorithms. Moreover, it is shown through simulations that our proposed scheme achieves similar symbol error rate performance to that of the standard multiple antenna transmitter with multiple RF chains under power limited single-user and multi-user transmission scenarios. Furthermore, it is shown that increasing the self-resistance of an EA to achieve stability is highly power inefficient.

Application of mathematical modelling methods for acoustic images reconstruction

The article considers the reconstruction of images by Synthetic Aperture Focusing Technique (SAFT). The work compares additive and multiplicative methods for processing signals received from antenna array. We have proven that the multiplicative method gives a better resolution. The study includes the estimation of beam trajectories for antenna arrays using analytical and numerical methods. We have shown that the analytical estimation method allows decreasing the image reconstruction time in case of linear antenna array implementation.

Load modulated arrays: a low-complexity antenna

This article describes promising recent progress in the area of massive antenna array architectures with low front-end hardware complexity. The presented technology enables the design and implementation of antenna arrays with large numbers of elements, while obtaining significant front-end hardware savings as compared to the conventional solutions. This newly appearing design approach could be used in order to design either massive arrays with complexity that would be prohibitive with the current technology, or smaller arrays that offer high spatial degrees of freedom and are suitable for future small yet powerful cell nodes. RF hardware architectures with a single RF chain are reviewed, compared, and found superior to conventional MIMO implementations in terms of cost, dissipated heat, and physical size. The proposed improvements on the RF side allow the merging of the two dominant cellular technologies of virtual (distributed) and massive (centralized) MIMO into a hybrid approach of antenna arrays that is suitable for both large base stations and small (possibly cooperative) units such as remote radio heads.

Simulation of the Acoustic Field of Antenna Arrays

The article considers the reconstruction of images by Synthetic Aperture Focusing Technique (SAFT). The work compares additive and multiplicative methods for processing signals from antenna array. We have proven that the multiplicative method gives better resolution. The study includes the estimation of beam trajectories for antenna arrays using analytical and numerical methods. We have shown that the analytical estimation method allows decreasing the image reconstruction time in the case of linear antenna array implementation.

Radiation Characteristics and Mutual Coupling of a Dual: Band Antenna Array Structure

In this paper, an antenna array structure consisting of a reflector plate and a number of printed dipole radiation elements is investigated. This antenna array implementation is suitable for the globally available 2.4 and 5 GHz ISM frequency band facilitating a variety of wireless applications. S-parameters and radiation characteristics are simulated and measured in details. The impact of the plane reflector on radiation patterns and the reflection coefficient are also investigated. Furthermore, mutual coupling effects between adjacent elements and the corresponding radiation patterns are studied for different antenna array configurations. Both simulated and measurement results are useful in antenna array design and antenna applications in wireless communications.

Utilization of antenna arrays in HF systems

Different applications of radio systems are based on the implementation of antenna arrays. Classically, radio di- rection finding operates with a multi channel receiving system connected to an array of receiving antennas. More recently, MIMO architectures have been proposed to increase the capacity of radio links by the use of antenna arrays at both the transmitter and receiver. The first part of this paper describes some novel experimental work carried out to examine the feasibility of ap- plying MIMO techniques for communications within the HF radio band. A detailed correlation analysis of a va- riety of different antenna array configurations is presented. The second section of the paper also deals with HF MIMO communications, focusing on the problem from a modelling point of view. The third part presents a sen- sitivity analysis of different antenna array structures for HF direction finding applications. The results demon- strate that when modelling errors, heterogeneous antenna arrays are more robust in comparison to homogeneous structures.

Spatial Correlation of Radio Waves for Multi-Antenna Applications in Indoor Multipath Environments

This paper presents the results of a concerted effort in characterizing the spatial correlation of radio waves detected by a multi-element antenna system in indoor environments. The number of arriving paths and their directions are first studied through a series of measurements. The results are then used in a simulation to obtain spatial correlation indoors. It is found that generally an antenna array positioned near the center of the room will experience more rapidly decreasing correlation with spacing, which is a desired trait. In addition, a linear array oriented perpendicular to the length of the room in general shows better characteristics in terms of faster slope of correlation compared to the one in parallel with the length of the room. The average correlation indoors is also found to be similar to the correlation function arising from the two-dimensional circularly distributed random scatterers proposed by Clarke. For practical implementation of antenna arrays in small terminals for indoor wireless applications, it is suggested that the inter-element spacing be made 0.3? in the least.

A Novel Circular Smart Antenna Array Implementation and its Analysis with Mutual Coupling

Based on genetic algorithm and method of moments (MoM), an efficient procedure is proposed in this paper for the optimal design of smart antenna elements. The configuration of a novel coaxial collinear printed dipole antenna is also proposed, which is used as an element in the circular smart antenna array. In our analysis, the effects of mutual coupling among elements are examined in detail, and the accuracy of our procedure has been checked in the design of experimental antenna arrays used in a TD-SCDMA system.

Use of an antenna array at customer stations to improve the capacity in a WLL network

Recent research on adaptive antenna arrays for telecommunications has opened the possibility of a new access technique: space division multiple access (SDMA). This multiple access scheme achieves an increase in the capacity of wireless networks making efficient use of spectrum. Usually, the implementation of antenna arrays is considered at base stations only (for practical reasons) in cellular mobile systems. However, the fixed nature of wireless local loop (WLL) systems allows the operators to take into account more specialized antennas for customer premises. In this paper the implementation of an antenna array at the user station is proposed as a mechanism to improve the system capacity. Different WLL configurations are analysed, whose performances are compared in terms of blocking probability. Obtained results are validated with theoretical models. After this, an evaluation is done from performance plots for analysed configurations. A significant improvement in the proposed configuration is observed from these plots. Copyright © 2000 John Wiley & Sons, Ltd.