Hybrid UHF Quad Antenna for Indoor Use

Amateur ultra-high frequency (UHF) directional antennas intended for indoor use are typically used in confined spaces. Also, their position and orientation often have to be changed, therefore they are exposed to frequent mechanical stress. For this reason, it is preferable that this type of antenna is lightweight, compact, with a mechanically reinforced (strong) construction. Also, it is desirable that the antenna has the best possible electrical and electromagnetic characteristics. This paper presents one of the ways in which the mechanical, electrical and electromagnetic requirements for amateur radio UHF directional indoor antenna can be simultaneously met. In the article, a relatively simple construction of the antenna is proposed. The antenna consists of two vertically stacked hybrid antennas from the Quad antenna family. The paper also presents an interesting choice of materials which ensures a mechanically reinforced (strong) construction and lightweight of the antenna. Numerical calculations and optimizations were carried out using 4nec2 software. Bandwidth and voltage standing wave ratio were determined by measurement.