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How Secure Is Your Wireless Network? Safeguarding Your Wi-Fi LAN by CCNA Lee Barken - CISSP MCP, CPA

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How Antennae Work

Antennae work by sending electrical charges back and forth across a conductor called an antenna. The electric field induces a magnetic field, which in turn induces another electric field, which in turn induces another magnetic field, and so on, as the wave propagates across a medium (such as air). This is called an electromagnetic field. How do you determine the appropriate size of the antenna? Because radio waves travel at the speed of light (a constant), the optimum antenna size depends on the frequency of the wave. Let's say that you wanted to build an antenna to broadcast signals for a radio station operating at 1000 kHz (a.k.a., 1 MHz) on the AM dial. 1 MHz means that the radio is operating at a frequency of 1 million cycles ...

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