What is the sleeve antenna?
The
sleeve antenna is a specific design of the radio wool antenna used for both the reception and the transmission of radio frequency signals. The design of two elements of the sleeve antenna is what the device gives its name. In its simplest and most common form, the antenna sleeve has a straight metal element, often rods or wires, located and centered into a straight metal tube that acts as a sleeve over the center element. While the sleeve antenna can be made to work with virtually any radio frequency, it uses most in high -frequency belt applications such as CB Radio Base Station or naval ship, radio antennas on the coast. First, with two separate elements, the sleeve antenna is classified as a dipole type antenna, which means it has two poles. Secondly, it is also classified as a half wave antenna, which means that the antenna is most suitable for receiving or trans-transmit on radio wavelength twice the physical length of the antenna. Third, these antennas that are nAminated vertically, they can receive and broadcast in all directions at the same time, making them members of the omnidirectional class antenna class. Finally, because both elements of the antenna share the same center line, it can be described as a coaxial antenna, which means that both poles have a common center axis.
Like all radio antennas, the sleeve antenna works on the principle of frequency resonance. Frequency resonance dictates that the specific transmission of radiofrequency frequency causes the specific length of the metal to resonate at the atomic level and generate an alternating electric current. This generated current, identical in structure and modulation with the original radio signal, then passes through a different electronics such as the radio, so the signal can be heard. Similarly, if the radio uses an alternating signal on a specific size of a piece of metal, the metal will resonate. Likewise, it transmits a signal in the form of radio waves that can in turn accept another antenna.
The range of radio wool frequencies that can resonate a piece of metal or antenna is called bandwidth. Because the sleeve antennas have a wide difference between the inner element and the outer element, they can receive and transmit a relatively wide range of radio frequencies. This attribute makes them useful in many applications, although the antennas themselves are not as effective in converting radio waves into electricity as other types that can have two or more elements fully exposed to radio waves.
Despite reduced efficiency, the antennas of the sleeve in many other constructions of the antennas do not have the necessary thin and spindle elements. This makes them physically more robust than most other antennas. As a result, they are most commonly used in applications where antennaamus to endure serious weather conditions and still function properly, for example on ships or on permanently mounted outdoor CB antennas.