Bibliography Radio design group,INC. "How it Works: Radios" retrieved from internet at http://www.radiodesign.com/radwrks.htm Nasa "How the mars microrover radios and antennas work" retrieved from the internet at http://mars.jpl.nasa.gov/MPF/rovercom/itworkst.html#rover-radio HSW media network "How radio works" retrieved from the internet at http://electronics.howstuffworks.com/radio4.htm American Radio Relay League"The Sun The Earth and the Ionosphere: What the numbers mean, and propagation predictions-- a brief introduction to propagation and major factors affecting it" Retrieved from the internet at http://www.arrl.org/tis/info/k9la-prop.html\ American Radio Relay League"Why a Beam Antenna?" retrieved from the internet at http://www.arrl.org/tis/info/pdf/7201036.pdf American Radio Relay League"Simple Gain Antennas for the Beginner" retrieved from the internet at http://www.arrl.org/tis/info/pdf/8108032.pdf University of Virginia department of physics "physics 606 : How things workII" retrieved from the internet at http://www.phys.virginia.edu/classes/606.ral5q.spring02/Physics606slides/lecture24.pdf