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Firstly, can someone let me know if this is correct. Regarding the ANT pin on an RF module, is this supposed to be connected to the GND pin via a wire (the aerial)?
Secondly, I take it that a sinusoidal current flows out the ANT pin to GND. Therefore, is it viable to connect ANT to an amplifier (for example a BJT) to boost the signal strength?
Finally, when a radio transmission power is specified (e.g. 100mW) what does this refer to? Is it simply the voltage across the aerial times the current or is it more complicated? (I expect it is the latter)
Marconi antennas are usually 1/4 wavelength long and require a path to ground. The ground plane itself acts as a reflector of energy, and combines with the directly radiated wave to create the overall radiation pattern. If the ground is dry or otherwise a poor conductor, a copper grid is generally laid out on the ground. The impedance of a 1/4 λ Marconi antenna is 36.6 Ω.
Notice that a Marconi antenna could be considered as a dipole antenna with one of the poles buried in the ground. The ground acts as a reflector to create the appearance of an buried antenna in the same way that a mirror creates the appearance of someone behind the glass. Increasing the antenna length has a significant impact on the radiation pattern:
The Antenna may connected both the ANT and GND pin depend on the type of Antenna design.
No-no-no!The aerial (ANTenna) should, in its simplest form, be a wire of a quarter (or half) of a wavelength going into the air (i.e. unconnected at the "far" end).Shorting it to ground won't hurt a receiver (just decreasing reception to almost nothing), but a transmitter will die from that treatment!
Can someone please explain to me how an antenna can work without current going through it? I assume that, because it isn't grounded, there is no current going through the wire.