FG4805

An antenna is an important and necessary component for any radio frequency (RF) system, such as the FG4805 antenna. The FG4805 antenna belongs to the family of RF antennas and is a helical antenna with a wide frequency range. It is among the RF antennas with the most features. This article describes the application field and working principle of the FG4805 antenna.

Application Field

The FG4805 antenna is a 50-Ohm impedance antenna that operates over a wide frequency range of 480MHz-520MHz. Its low VSWR (Voltage Standing Wave Ratio) performance makes it an ideal choice for both indoor and outdoor applications, such as in vehicles, industrial machinery, medical equipment, cell tower base stations, satellite broadcasting, and radio broadcasting. It is also suitable for applications in harsh environments since it has a rugged construction.

Working Principle

The FG4805 antenna is a dual-element helical antenna. It consists of two elements, each of which is 3/4 wavelength long. The two elements are mounted in a staggered formation and oriented to radiate horizontally, forming an omnidirectional pattern. The antenna elements are wound in a helical fashion, giving them the ability to tune to the desired frequency range. This is accomplished by adjusting the length of the elements until the antenna has a VSWR of less than 2:1. This design also makes the antenna more efficient in terms of radiation pattern and gain.

The omnidirectional radiation pattern of the FG4805 antenna is generated by the superposition of the fields from the two antenna elements. The two elements are separately driven, resulting in circularly polarized radiation. The two perpendicular components of each element\'s field combine to create the desired omnidirectional radiation pattern.

The design of the FG4805 antenna makes it well-suited for a variety of applications requiring wide frequency coverage, low VSWR, and easy installation. Additionally, its robust construction makes it an ideal choice for use in harsh environments. As a result, the FG4805 is a widely-used antenna in many RF systems.