Antennas:

In order to obtain the best gain, whether through broadcast or reception, it is necessary to use correct antennas that are appropriate to the frequency band you wish to use.
There is a wide variety of antenna.
There are basically two types of antennas, directional antennas and isotropic antennas.
The directional antennas have a better gain than Isotropic antennas because
directional antennas can be precisely directed to the transmitter or receiver.
An isotropic antenna transmits and receives in all directions (360°).
To make "Long Distance" contacts, it is preferable to use directional antennas.

Directional antennas are also used by the TV, GSM transmitters, and for WIFI applications.

Here are some photos of wide-band antennas:

“Discone” Antennas (Specially designed for the reception)

This kind is always Isotropic and can generally receive signal between 30 and 1300MHz.

 

 

 

 

 

 

 

 

 

 

 

 

Some Homemade models:

                                                                                                                          

   This antenna is used to receive
   signals between 400 and 1300MHz.

 

 

 

 

 

 

 

                                                 

This homemade antenna is designed to receive three frequency bands:

86, 150 and 460MHz.

It's one of the best antennas for wide band reception.

 

 

 

 

 

 

 

 

 

 

 

Here are the specifications for this antenna:

 

 

 

 

 

 

 

 

The length of each arm depends on each frequency.

 

Some Wifi antennas:

A “Ricoré” antenna (specially designed for a Wifi Network in 2.4GHz)

 

 

                                                                                                              

It is a directional antenna with a better gain than a traditional Wifi antenna.

Another similar antenna: the “Pringles antenna” for the Wifi:

                                And it works very well!