This article includes a report from an investigation of the performance of a Marconi antenna design that I had carried out in 2020. The transceiver radio system was based on a license free ISM/SRD LoRa radio system. Since the product was for a customer who would be using the radio links in North America, the operating frequenct band was set at 460MHz, in the UHF band. The significance of this operating frequency is from the allocation of the radio spectrum between the Federal Communications Commission (FCC) and the National Telecommunications and Information Administration (NTIA) in the USA as detailed in the US Government FCC website.
Whilst the original implementation did meet requirements in terms of range. The objective of this exercise was to go beyond the first order principles used to implement the 1/4-wave whip antenna also known as the Marconi Antenna (or Monopole) to improve the reach of this design.
My findings captured in this report were very interesting indeed. Because there was more to a Marconi Antenna than just the length of the wire used as the transmitting antenna. In fact not only the gauge or diameter of the antenna element (copper wire) but the virtual ground plane were very significant indeed. I state ‘virtual ground’ because on a PCB that measures approximately two inches and for the final device to be mounted on a pole of some kind, the ground plane is merely made up of a relatively small area of copper ground plane on the PC Board. More details about this can be found in the report.
Furthermore. This experiment led me to understand that no matter how they’re marketed by manufacturers, generic antennas are not as efficient as one that might be designed specifically for an application.
This report has been made public since the end customer received a distilled version of it and in many ways I wish they would notice it and hire me to improve their systems!! 🙂