Circular FM Broadcast Antenna
In the world of RF, the antenna is one system that is very important because the antenna can determine how far the signal goes. The antenna is an element which radiates the signal. Electromagnetic field signals can be polarized in a circular, vertical, and horizontal. Here is the FM broadcast antenna is circularly polarized, is used in FM transmitter in the frequency range 88-108 MHz.
Antenna and Material Specifications
Antenna made of copper pipe (pipe AC), the reasons for using these materials are easy to create circular shapes. Diameter copper pipe is 0.5 “.
Circular FM Broadcast Antenna
This antenna has a gain of about -1.5 dB (isotropic dipole). Increasing the amount of gains made through stacks of more than one antenna. More and more antennas are stacked, it will increase the amount of gain antennas, so that will be able to double the ERP (Emmition Radiating Power).
Antenna Dimensions
For the antenna size can be seen on circular FM broadcast antenna diagram below:
Circular FM Broadcast Antenna Diagram
Signal amplification
Gain is based on the antenna gain in Decible (dB). ERP is calculated by multiplying the power of the transmitter with antenna gain. When four antennas stacked estimated to have a 3:12 dB gain, 5.12 dB for six antennas, and 6.40 dB for eight antennas. (3dB= 2, e.g. Antenna Gain for eight antennas =6.40/3 x 2 = 4.26)
ERP = Transmitter Power (Watt) x Antenna gain.
Read more : Dipole FM Antenna – FM Radio Transmitter.