Satellite Modems

Overview

Satellite modems are communication devices that use a satellite as a gateway to the destination device. This page focuses on satellite modems designed for embedded applications.

They typically have tight technical voltage supply specifications (such as 40mVp2p voltage ripple and the ability to momentarily provide 1.5A of current during transmit mode).

Terminology

Term Description
Globalstar A popular manufacturer of satellite modems.
Iridium A popular manufacturer of satellite modems.
LEO Low earth orbit. This is an orbit which has an altitude between 160 and 2,000 kilometers above the earths surface.
TNC A type of RF connector used for the antenna.
SMA A type of RF connector used for the antenna.
Quadrifilar A type of antenna used for satellite communications.

 

Iridium

The Iridium 9602 and 9603 are both burst-data only satellite modems designed for embedded systems.

When the 9603 is in transmit mode, it can draw up to 1.5A (for an period of around 8.3ms), with an average transmit current of 190mA. When receiving, they can draw 195mA peak and 45mA average.

Antennas

Quadrifilar

Quadrifilar antennas can come in packages which are cylindrical with dimensions such as 18mm in diameter and 48mm in length.

Posted: October 9th, 2013 at 3:00 pm
Last Updated on: October 9th, 2013 at 4:20 pm