The invention of the Quagi antenna was one of the most appreciated inventions of its time. The design of the Quagi antenna that was published long before its invention indicated to combine the Yagi and cubical quad features for the formation of this new Quagi Antenna. This design was approved in 1972, which led to the invention of the Quagi antenna.
Quagi antennas are the simplest, easiest, and effective antennas. Since these antennas are used for communications purposes, these antennas are also called directional antennas. Quagi antennas give a gain of 14.52 dbi, which is a good efficiency and a front-back ratio and is much better than that gain of a reference antenna.
Just like the loop antennas, Quagi antennas are built in a square shape. At the back of the Quagi antenna, there are reflectors and deflectors of a quad antenna. The Quagi antennas now available in the market have the eight-element Quagi having the length and spacing that are a very good compromise between the bulk and gains. After many experiments and changes, the modern Quagi antenna is efficient enough to work for frequencies above 144 MHz.
The Quagi antenna was used widely in receiving the signals for a TV, and everyone has experienced using a Quagi antenna. Quagi antennas help give continuous coverage without any distortion, and it is also used to operate HAM Radios and Handheld HAM Radios. The main function of a Quagi antenna is to collect the signals that could result in a smooth transmission. About two decades ago, the antenna was usually set up at the roof of the house from where it got straight signals from the satellite, and it was connected with the TV. When the antenna received strong signals, then the transmission was continuous. If the antenna was not set properly, then the transmission stopped. You can adjust the Quagi antenna by moving in and setting it in a specific position.
The most amusing thing about the Quagi antennas is that you can also design them yourself after learning some tips and tricks. The base of the Quagi antenna is a boom that is made up of wood. You need to take the dimension of the wood as per your frequency ranges. Next, you have to fix the quad elements made of copper wire to support the current maxima. Then you have to mount the directors through the boom; these directors should be made up of metal wires of 3 mm diameter.
All these wires and circuits are fixed with screws to give permanent installation. In constructing a Quagi antenna, the most important element to be careful about is the accuracy of long wires. For the higher frequencies such as 432 MHz, even a 3mm measuring error can affect the antenna’s performance. You also have to make sure that all the circuit elements are in the right direction, such as the longest director goes closest to the driven element.
All in all, quagi antenna has proven to be consistent in its performance in different types of VHF-UHF services. The best part is that it gives highly efficient performance in a reasonable budget and easy to produce design. We hope that this article helped you in understanding the construction and application of a Quaqi antenna.