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What is antenna inductance?
1 : the inductance of an antenna, its value varying at different frequencies as evidenced by the current distribution. 2 : the inductor or loading coil in an antenna circuit.
What does an antenna loading coil do?
A loading coil or load coil is an inductor that is inserted into an electronic circuit to increase its inductance. The term is also used for inductors in radio antennas, or between the antenna and its feedline, to make an electrically short antenna resonant at its operating frequency.
What is the range of inductor?
Inductors have values that typically range from 1 µH (10−6 H) to 20 H. Many inductors have a magnetic core made of iron or ferrite inside the coil, which serves to increase the magnetic field and thus the inductance.
Is a capacitor an antenna?
Yes, parallel-plate capacitors are dipole antennas (especially true at self-resonance, usually up in GHz.) If the plates are smaller than quarter-wave (or the gap is smaller,) then an impedance matching network would be used to boost the volts for electrically-small dipole-mode.
Can you coil an antenna?
A loading coil may be used, on its own or in conjunction with a capacity hat, to tune the antenna to resonance at a lower frequency. One coil placed in the center or at the base of a single-band vertical antenna is sufficient, but a single-band dipole will require two coils – one in each element of the dipole.
What is meant by antenna loading?
[an′ten·ə ‚lōd·iŋ] (electronics) The amount of inductance or capacitance in series with an antenna, which determines the antenna’s electrical length. The practice of loading an antenna in order to increase its electrical length.
How is the gain of a UHF antenna measured?
This is probably the most important aspect of a UHF antenna. Gain is measured in decibels (dB). If you are trekking through the hilly countryside or scouting across the vast outback it is going to determine what gain you need. This is around the 3-5dB range and is best suited for hilly terrain.
How to make an inductor a good antenna?
The simplest way to guarantee that the field is strong at a distance of 1/4 wavelength is to build an inductor which acts like a dipole electromagnet. But make an electromagnet where its magnetic poles are roughly a half-wavelength apart. Buy yourself a ferrite rod that’s 1/2-wave long, then use that rod as your inductor core.
What’s the best range for a UHF antenna?
This is around the 3-5dB range and is best suited for hilly terrain. You need to picture the signal as an apple, it is wide but short in distance. This is great for hills as it give you the height and depth required for communication at different levels of elevation.
How is an external antenna tuner used in a HF network?
An external antenna tuner is often used in conjunction with HF antennas to tune antennas to resonance within a band. In most cases, these are π or T networks in which a variable inductor and capacitors are used to tune for the lowest standing-wave ratio as seen by the transmitter.