Magnetic loop antenna

What are magnetic antennas? The secondary is the main loop, and is the actual antenna. This outer conductor is closed by a variable tuning capacitor. The small loop antenna is known as a magnetic loop since it behaves electrically as a coil.

It couples to the magnetic field of the radio wave in the region near the antenna, in contrast to monopole and dipole antennas which couple to the electric field of the wave. It will tune from 50MHz to about 200MHz, although tuning is fiddly because of stray capacitance of your han and also must be done with an insulated tool.

An antenna analyzer is really needed for building this loop. The magnetic loop couples to the to the magnetic field of the radio wave in the region near the antenna, in contrast to a monopole or a dipole which couple to the electric field of the wave. Radio waves travel by a wave of electric and magnetic fields at degrees to each other.

Our regular antennas work by "recieving" the electric field portion of the radio wave. A small current is transduced on the antenna and the reciever amplifies it and converts it to audio. The loop antenna is basically an LC-circuit that has to be tuned to resonance on the desired operating frequency. The loop by itself is an inductor that has the shape of a closed- loop.

The generic formula for the resonance frequency of an LC-circuit is shown in Fig.

Note the duality of the "L" and the "C" in this formula. The aim of any receiving antenna is to convert an electromagnetic wave into a voltage. Loop antenna principle. A magnetic loop antenna is a winding of copper wire around a frame (for air-core loops ) or around ferromagnetic material (for ferrite loops ). The best thing about these magnetic antennas is that they are very quiet, and electrical interference can’t affect them.

MHz, the loop described here is directional, does not require a radial system, and stands just 1. The combination of an inductor (a wire has inductance, but a coil of wire has more) and a capacitor (two conductors separated by an insulator) in a circuit will resonate or ‘ring’ at a certain frequency. A loop antenna is actually sensitive to the magnetic field and not the electric field (it is also called a magnetic loop ). It outputs a voltage proportional to that field.

The “primary” of this transformer is a small loop of wire, fed by standard Ohm coaxial cable (coax) that goes to your HF transceiver. Hence the widely used term “magnetic loop” antennato signify this field discrimination to the components of the incoming incident M waveE.

Antenna theory treats the loop as the electrical conjugate of the dipole, i. And because the loop antenna is somewhat the "dual" of the dipole as discussed earlier, the magnetic fields are strong in the near field of the loop antenna. These magnetic fields ultimately give rise to the antenna radiation, and since they are somewhat immune to the human body, loop antennas tend to be much more robust in terms of performance when they are placed near a human.

It may be in any shape such as circular, rectangular, triangular, square or hexagonal according to the designer’s convenience. Large loop antennas are also called as resonant antennas.

Magnetic loop antenna enables the radio to pick up waves and convert them into sounds.

In contrast to the MLA M he. W6LVP amplified receive-only magnetic loop antenna (boy is that mouthful): The W6LVP mag loop is a complete receive antenna system delivering top-of-the-line performance to amateur radio operators and SWLs. Here is a simple table comparing my realized 6. The smallest antenna described for metres was a magnetic loop. This article provides all the details needed to build your own.

Description Able to cover allRead More. This interesting feature makes the ground plane losses very low and generally this antenna has little dimensions.

Small transmitting loop antennas, commonly called " magnetic loops" or "mag loops," can give surprisingly good performance when they are carefully designed and constructed. Although this online calculator is intended to assist with designing and building homemade, ham radio loop antennas for use in the HF bands, magnetic antennas have been.

Works either in Standard and Metric units, and let you choose on material, and loopRead More.