TIL-TEK Antenna Seminar

Instead of saying "cycles per second", we use the word Hertz (abbreviated Hz) in honour of Heinrich Hertz who discovered radio waves. Also, since we are dealing with high frequencies, we use prefixes like kilo (1,000), Mega (1,000,000) and Giga (1,000,000,000) in front of Hertz, to further simplify the terminology. 5 cycles per second = 5 Hz 5,000 cycles per second = 5 kHz 5,000,000 cycles per second = 5 MHz 5,000,000,000 cycles per second = 5 GHz We know that radio waves travel at the speed of light (~186,000 miles per sec. Or 3 x 108 meters per sec.) and we can measure the frequency of the radio waves, therefore we can find out how far the wave travels in 1 cycle by dividing its' speed by its' frequency. We call this a wavelength (abbreviated ?) An antenna is a device which transforms electromagnetic signals from a transmission line, into electromagnetic waves radiating into free space, (transmit mode) and also collects electromagnetic waves, transforming them into electromagnetic signals and sends them to the transmission line. (receive mode) This is all the antenna is designed to do; it is a passive device. Antennas do not amplify, they simply focus radio energy