First, we are not giving a history lesson here on antennas at this time (maybe later).
Instead, we will be using wikipedia as a reference. (please consider
donating to them, they do a much needed job for little regard)
An antenna (or aerial) is an electrical device which converts
electric power into radio waves, and vice versa. ("https://en.wikipedia.org/wiki/Antenna_(radio)")
There are a number of terms and things that will be very helpful to learn at this point.
We will begin with these and then go back and discuss different types of antennas and their basic pluses and
minuses. I know it will be a little overwhelming at first, but in time most of these will become second nature.
For now just mouse over the term you wish to read and the definition will appear.
List of terms
Antenna and Wave propogation
The electronic signals generated by antennas travel through the air similar to waves on the ocean. There are things
in the atmosphere (and in the antenna design or the earth itself) that affect how those waves travel.
This one has some really complex definitions if you look it up but for our purposes just think of Attenuation as the decrease in power of a signal as it moves away from the source.
Measured as dB over a length of measurement: db/feet, db/meters
For us this is a measurement of a continuous set of frequencies. for example the 6 meter band is from 50-54MHz so the bandwidth for 6 meters is 4MHz. Another example is the human voice can create sounds from roughly 300Hz to 3400Hz so the bandwidth of the human voice is approximately 3100 Hertz.
(or antenna efficiency) is the measure of the efficiency with which a radio antenna converts the radio-frequency power accepted at its terminals into radiated power.(Wikipedia)
(or electrical impedance) is basically the resistance of a medium to the flow of power. i.e. the impedance of a coax cable (we will discuss this later under cable and cords)
For a given piece of equipment there is an impedance, be it power supply, antenna, cable, etc., Matching is taking some form of resistance or capacitance or the like and making the impedance the same or similar. This allows for maximum power or signal strength to be transferred from one piece to the next with minimal distortion.
This is not the direction in which the wave moves but in which directions it oscillates relative to the Earth. ie. as the wave moves out from the antenna does it oscillate from side to side (horizontal) or up and down (vertical).
An electromagnetic radiation wave that oscillates at a frequency that puts it in the radio frequency range. This is below infrared light or 300GHz
Google does a good job with this one: The radiation pattern is a graphical depiction of the relative field strength transmitted from or received by the antenna. Antenna radiation patterns are taken at one frequency, one polarization, and one plane cut.
This is the frequency at which a maximum power is allowed to transfer. Or in terms of an antenna, it is when the antenna is of a length to allow standing wave formation by current and voltage moving from one end of antenna to the other.
List of antenna types/names
The Concept is thus: take pieces of Coax 1/2 Wavelength and soldering the center conductor to the shielding alternatively
and placing it inside something to keep it standing.
"it consists of two identical conductive elements such as metal wires or rods" (Google) Which are then powered by separate
portions of the balanced feed line
a type of monopole antenna with one single wire (or whip) going vertically with horizontal rods extending typically horizontally from the base attached to the opposite side of the feedline
As the name suggests this is an antenna with a horizontal section at the top with a longer vertical section fed from the
This is a hypothetical antenna that radiates power in all directions equally. These are not actual real physical antennas,
it is just an ideal that is used as reference for antenna gain
As the name suggests this antenna is shaped like a "J" with a 1/2 wave long section atop a 1/4 wave double section.
"Matching" is done by moving the connection to the feedline back and forth along the 1/4 wave sections until an impedance match is
Is an array of elements(poles electrically connected in parallel) that progress from longest(lowest frequency) to the shortest(highest frequency)
Here we are talking specifically about Resonant loop antennas. an antenna similar to a folded diapole but is in a circle and typically fed from the bottom or the side
very similar to the loop antenna, the quad is typically built on sturdy central X structures with the conductive "loop" around the outside. These antennas will have one driven element and one or more direction elements
An antenna that is shaped like a diamond. the antenna is fed from one of the small angles, with the other one either left open or crossed with a resistor
This is just a slanted Dipole antenna, typically at a 45-60 degree slope. the feedline must be at a 90 degree angle to the antenna for at least 1/4 wavelength. typically it is fed from the center like a dipole.
This is a form of Monopole antenna it has one radiating element that is vertical and typically mounted on a conductive surface, like the sheet metal of a car. one side of the feed line is attached to the vertical element and the other side is attached to the conductive surface. monopole antennas are a very widely used antenna configuration and i would suggest further research on the subject when you have time.
As the name says this is simply a piece of wire, stranded or solid, that is strung up in the air where space allows. typically with this type of antenna the other side of the antenna terminal is connected to earth ground. These are great simple receiving antennas for long wave- short wave bands but typically are not good transmitting antennas due to the fact that they are not "cut" for a specific wave length
when searching for this look for a "Yagi-uda" antenna. This is an antenna array actually with one driven element and a reflective element behind it and directors in front. This design has a good amount of gain and directionality compared to a dipole. This is a very widely used antenna configuration and if your curious, I would suggest doing further research on it.
Here are a few books that you might want to look into when you get these down pat. Some of these books are not for beginners.