Research on HF antenna blockage effects and their alleviation

Effect of Buildings on the Radiation Characteristics of MF Broadcast Antennas

“…The results presented herein focus on the radiation patterns of the monopole and the array in the presence of buildings; all the diagrams include the radiation pattern of the corresponding antenna in free space, for the sake of comparison. It was found that the radiation pattern, among other antenna characteristics, such as the gain and the voltage standing wave ratio (VSWR), were particularly influenced by antenna blockages, not only at the HF band [2], but also at much higher frequencies [3][4][5].…”

“…Table 1 offers a comparison of the study presented herein and pertinent works found in the literature. The first three lines in Table 1 comprise three studies [2,11,12], respectively, which, together with the current study, deal with the impact of buildings either on the radiation characteristics of antennas or, more generally, on the far field at MF or HF frequencies. However, ref.…”

“…with 2 , and r = ρ 2 + z 2 are depicted in Figure 1a. For the array, the corresponding non-zero components of the far field are:…”

“…Although the problem of the propagation of MF (medium-frequency) and HF (highfrequency) waves in built-up areas has long been considered [1], there is a very limited number of available studies focusing on the effects one should expect on the radiation characteristics of MF and HF broadcast antennas due to blockage [2]. Most papers that deal with antenna blockage focus on frequencies higher than 1 GHz [3][4][5][6].…”

“…2022, 12, 6525 2 of 14 HF direction was analyzed by using the method of moments (MoM) and the physical optics (PO) technique [15]. Recently, blockage effects on HF antennas were studied; their influence on the radiation characteristics was analyzed and a relationship between the antenna and the size of the blockage was determined [2]. Furthermore, the modeling and simulation of the influence of buildings on the signals of navigation devices for aviation were presented in [16][17][18].…”