Wireless: Ch 4 cont.

Short one today, as we had a test and Jerry talked quite a bit on unrelated stuff.  Also, sorry about the format, the keyboard I had was sticky and I could not type well, I had to copy/paste from the powerpoint slides. 

Antenna Characteristics

Types, sizes and shapes

Passive antennas

–The most common type

–Constructed of a piece of metal, wire, or similar conductive material

–Does not amplify the signal in any way

–Directional gain

•Passive antennas radiate the RF energy supplied by the transmitter in one direction

•Exhibits an effective gain that is similar to amplification of the signal

Wireless: Start of Ch 4

Supplemental notes for the review of Ch 3. 

High pass aka low cut

Low pass aka high cut

The spike or raised area on any graph shows the BLOCKED frequencies.

Chapter 4 start

Gain and Loss

Understanding RF signal transmission involves the strength or power with which the transmitter is sending out the signal, the amount of reduction in signal strength caused by cables, connectors, and other components, the transmission medium and the minimum strength of the signal required by the receiver to be able to properl recover the data sent by the transmitter. 

An amplifier boosts the power of a signal, called a gain.  Cables and connectors offer a resistance to the flow of electricity and tend to decrease the power of a signal (loss).  Signal power changes logarithmically and gains and loss are relative concepts.  You need to know the power level of the signal at two different points.