# Optimization of Different Deployments and Resolution of Antenna Arrays in SWIPT
## 1 Introduction  
Millimeter wave (mm-Wave) communication is very promising in terms of high data rate and it is being studied as a key 5G technology to accommodate the expansion of the Internet of Things (IoT) [1, 2, 3, 4, 5, 6, 7]. Because of their smaller wavelength, massive antennas can be deployed in the limited space at the mm-Wave. Nevertheless, this does cause serious path loss and shadow fading at mm-Wave. The technique of beamforming by antenna array was used to solve those problems at the mm-Wave in recent years. In IEEE 802.11 ad, the codebook was set in the protocol for quick pairing and eventually it was extended to a 5G technology application. In addition to the fixed pattern of the codebook, it can also be adjusted by the algorithm for beamforming according to the environment [8, 9].  
In IoT applications, numerous smart devices were deployed in mm-Wave worldwide for wireless communication. Among them, some devices use low-power design and power harvesting is considered as a solution for providing a perpetual and effective energy supply. As a result, the wireless powered transfer (WPT) and the simultaneous wireless information and power transfer (SWIPT) have been widely investigated in recent years [10, 11, 12, 13, 14, 15, 16, 17, 18]. In [19], the coverage analysis for energy-harvesting by unmanned aerial vehicle cellular networks at millimeter-wave communication was investigated. The authors in [20] developed a framework to study the security, reliability and energy coverage performance of downlink mm-Wave simultaneous wireless information and power transfer unmanned aerial vehicle (UAV) networks. In [21], the authors used the Nakagami fading channel to analyze energy harvesting performance in low-power devices powered by a mm-Wave cellular network. The problem of hybrid beamforming designed with the low-resolution phase shifter wasinvestigated in [22]. In ref. [23], the optimal analytic solution with the signal-to-interference plus noise ratio (SINR) constraint was presented for narrow band signal. The authors in [24] addressed the energy efficiency (EE) optimization problem for the SWIPT multiple-input-multiple-output broadcast channel.  
However, most papers have only dealt with the optimal analytic solution with some constraints for the narrow band signal and considered the stochastic channel in their analysis. Different adjustments in terms of feed length and the deployment of different antenna array shapes have not yet been simultaneously investigated in the literature with regard to SWIPT systems. In this paper, three different wide-band antenna arrays with variable resolutions were used to generate the array pattern for some simple IoT sensors. We optimized the power harvesting efficiency under the constraint of the BER by self-adaptive dynamic differential evolution (SADDE).  
The system model and the deployment of antenna arrays are presented in Section 2. Section 3 explains the SADDE and the objective function. In Section 4, numerical results for three different deployment cases with high resolution and low-resolution feed length by evolution algorithm are presented. The system quality and harvesting power are compared. Conclusions are given in Section 5.