Determining the Correct Satellite Dish Size

The size of the satellite antenna (dish) limits the amount of data that you can carry over a circuit. To choose the antenna size and amplifier power is a complicated calculation based upon the VSAT location relative to the satellite power footprint, the power of the satellite and the frequency band. When we know our clients needs and all of the other parameters we can guide their decision.

Satellite bandwidth is not cheap and some companies have designed a product that seems to offer cheap bandwidth. Their solution is to sell shared bandwidth. In other words they will buy 1 Meg from the satellite owner and resell this same bandwidth ten times — they gamble that not all of their clients will need bandwidth at the same time. At peak times this gamble will fail and the clients are left competing for the limited bandwidth space. If the client is running VoIP telephone service, the conversation is broken up and choppy, if they are running data the download speed becomes very slow.

Each satellite beam coverage pattern has power and sensitivity contours which are fundamental to the dish size required, so your location is important. At the outer, lower level contours larger dish sizes are required. In order to transmit a sufficiently powerful signal to the satellite you need a combination of transmitter power from the Block Up Converter(BUC) measured in watts, plus a dish size with enough gain to transmit the size of signal needed. There can be a trade off between a smaller dish and high power amplifier or larger dish and low power amplifier. In our design we address all of these facts, giving you enough information to make the choice that is best for your business.

Choosing the wrong antenna (dish) size can result in much higher monthly bandwidth fees. Often a savvy client will pay more for the equipment at the beginning knowing that their lower monthly bandwidth costs will pay back their original investment in just a few months.