A loop antenna is actually sensitive to the magnetic field and not the electric field (it is also called a magnetic loop).
They form another antenna types, which features simplicity, low cost and versatility. You l'll find loop in various shapes; square, circle, triangular, etc.
Widly used up to 3 GHz.. electrically small C<0.1 lambda , electrically large C~lambda. Broadcast AM (tube or transistor) radios are usually equipped with ferrite loop antennas. Such Magnetic Loop antenna are widley used in WIFI antennas too.
Know how to solve Maxwell equations ,Gauss' law for electricity and magnetism? Ready-made and easy to use calculation programs.
Many way's to build your Magnetic Loop. There is a lot of information available on the net, concerning Magnetic Loop Antennas.
Good books about Magnetic Loops are the ARRL antenna book Chapter 5 tabel 3.
And the Rothammel Antennabook.
Described a lot of theory and design, on the Magnetic fields, Magnetic Loop and shielded loop antennas, formula's etc. Also the importance of direction finding antenna's (handy for searching QRM / man make noise near your QTH).
The best way to success is: Make first, several small Magnetic Loops for example for 2 meter or 70 cm. Using WICU pipe ( 12/15/22mm
or thicker) or 6mm thick copper oil pipe, This is made from a soft red copper material and easy
to bend, and to process.
Advantages: - Easy to build - Good RX (High Q) - Reduction of man make noise - Small size, handy in small gardens .
Disadvantages: Small bandwidth - Dangerous high voltage on the capacitor ( 100 watt = 3 Kv ) - Strong magnetic field, keep distance by high power 100 watt or more.