A feeder system is a system consist of RF Cable(Balance or UNbalance), Duplexer system, Combiner/Spliter, Dummy load and Reject Load.
An antenna is a specialized BALANCE tranduser of load that converts radio-frequency(RF) fields into alternating current(AC) or vice-versa. There are two basic types: the receiving antenna, which intercepts RF energy and delivers AC to electronic equipment, and the transmitting antenna, which is fed with AC from electronic equipment and generates an RF field to be radiate out to the receiving antenna. An antenna is typically designed to radiated specified frequency that needed to and the performance is all depends on basically its gain, FB Radio(for Beam), back and side NULL(for beam) and bandwidth(BW). For instance, if a vertical antenna is cut to radiate 146MHz. If its BW is 2MHZ, then the total coverage frequency will be from 145MHZ to 147MHZ(Up 1MHz and Down 1MHZ) operable with minimal SWR.
There are mainly few type of basic antenna that used in the wireless field.
Omni directional antenna->Vertical commonly 1/4 and 5/8
Directional Antenna ->Yagi-Uda, Cubical-Quad, Horn-feed parabolic and similar.
As designed the antenna is usually fed by 50 ohm UNBALANCE coax RF cable from the source, in this case a transceiver to radiate the RF energy generated. A matching device is need to be placed in between to match impedance between the transceiver and the load. In this case the antenna. Such device called BALUN(BAlanceUNbalance).
A matched feeder to antenna(load) system will have a 100% transfer of RF power without any reflected power travel back down to the source ie. transceiver.
A unmatched feeder system will lead to RF reflection back to the transceiver which known as SWR(Standing Wave Ratio), which is a ratio between the forward RF power to the Reflected RF Power. In VHF system the SWR of 1:1 to 1:5 is acceptable. 1:1 is a perfectly matched system. In HF the SWR of 1:1 to 2 is acceptable.
Measurement: In RF feeder system typical measurement that usually carried out by RF engineer or Amateur Radio will be the total Forward Power, Total Reflected Power, SWR and finally the spectrum analyzing.
Article by: 9M6WST
An antenna is a specialized BALANCE tranduser of load that converts radio-frequency(RF) fields into alternating current(AC) or vice-versa. There are two basic types: the receiving antenna, which intercepts RF energy and delivers AC to electronic equipment, and the transmitting antenna, which is fed with AC from electronic equipment and generates an RF field to be radiate out to the receiving antenna. An antenna is typically designed to radiated specified frequency that needed to and the performance is all depends on basically its gain, FB Radio(for Beam), back and side NULL(for beam) and bandwidth(BW). For instance, if a vertical antenna is cut to radiate 146MHz. If its BW is 2MHZ, then the total coverage frequency will be from 145MHZ to 147MHZ(Up 1MHz and Down 1MHZ) operable with minimal SWR.
There are mainly few type of basic antenna that used in the wireless field.
Omni directional antenna->Vertical commonly 1/4 and 5/8
Directional Antenna ->Yagi-Uda, Cubical-Quad, Horn-feed parabolic and similar.
As designed the antenna is usually fed by 50 ohm UNBALANCE coax RF cable from the source, in this case a transceiver to radiate the RF energy generated. A matching device is need to be placed in between to match impedance between the transceiver and the load. In this case the antenna. Such device called BALUN(BAlanceUNbalance).
A matched feeder to antenna(load) system will have a 100% transfer of RF power without any reflected power travel back down to the source ie. transceiver.
A unmatched feeder system will lead to RF reflection back to the transceiver which known as SWR(Standing Wave Ratio), which is a ratio between the forward RF power to the Reflected RF Power. In VHF system the SWR of 1:1 to 1:5 is acceptable. 1:1 is a perfectly matched system. In HF the SWR of 1:1 to 2 is acceptable.
Measurement: In RF feeder system typical measurement that usually carried out by RF engineer or Amateur Radio will be the total Forward Power, Total Reflected Power, SWR and finally the spectrum analyzing.
Article by: 9M6WST
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