Mixing LT Spice and MMANA-GAL, what a clever idea 👍! I like to build my own transmitters, antenna tuners and antennas too. Thanks to your explanation : I am now able to simulate the whole thing 😁, and with free tools ! 73, F1SOC
👍 Another thing worth being mindful of when measuring antennas is common mode current, when the external side of the coax cable work as part of the antenna. Making baluns that will reduce this current is another fascinating topic for future videos.
I made me an antenna cable with plenty of ferrite clip absorbers for measuring purposes. Looks funny like a pearl chain and is quite heavy but quite effective up to 100 MHz.
The modelling of antennas like MMANA-gal does is fascinating - putting bits of electrically unconnected conductors of certain lengths at certain distances from the driven conductors affects things in profound ways (which is how Yagi-Uda "TV antennas") work, they're just a dipole in the middle with a bunch of unconnected metal rods on either side)!
5:10 A half-wave dipole has a theoretical impedance of 73 + 42.5j. In practice, the dipole is shortened until the imaginary reactance goes to zero, at which point the radiation resistance will be below 73 ohm.
Indeed you are right... the ideal, infinitely thin, dipole impedance at L/2 is ~73+42.5j; you can get it to resonate at a slightly smaller length, where the impedance will be ~70R+0j
Just curious. I've tried to replicate the LTspice model, but R1 is always generated in the netlist before "subckt" block (independent of the block positioning) and the program can not find the definition. Is there an extra requirement in settings or something else to implement such a frequency dependant model?
The same happens in my case as well, the resistor is first; however, its not a "resistor" but rather a subcircuit - the resistor component is set to be of "X" type - Ctrl+Right click on the component and set the prefix to "x". Let me know if it works out.
i am a materials scientist, and was wondering the state of antenna research now. do you have any insights on the materials aspect? Do you need a more conductive material? A material with variable impedance or capacitance? hehe thanks
Mixing LT Spice and MMANA-GAL, what a clever idea 👍!
I like to build my own transmitters, antenna tuners and antennas too.
Thanks to your explanation : I am now able to simulate the whole thing 😁, and with free tools !
73, F1SOC
👍 Another thing worth being mindful of when measuring antennas is common mode current, when the external side of the coax cable work as part of the antenna. Making baluns that will reduce this current is another fascinating topic for future videos.
I made me an antenna cable with plenty of ferrite clip absorbers for measuring purposes. Looks funny like a pearl chain and is quite heavy but quite effective up to 100 MHz.
The modelling of antennas like MMANA-gal does is fascinating - putting bits of electrically unconnected conductors of certain lengths at certain distances from the driven conductors affects things in profound ways (which is how Yagi-Uda "TV antennas") work, they're just a dipole in the middle with a bunch of unconnected metal rods on either side)!
Interesting! Many thanks for sharing how to import antenna impedance to SPICE.
Very interesting argoument! Please continue this Antenna's topic! Cheers from italy!
Oh boy, I'm getting Network synthesis flashbacks. That's where I always drew the line between science and black magic.
This brings so many nice memories. Thank you.
This is the best explanation of an antennas functions I’ve ever found! Thanks!!
FesZ, can you show us how to model a bifilar pancake coil in LT Spice?
5:10 A half-wave dipole has a theoretical impedance of 73 + 42.5j. In practice, the dipole is shortened until the imaginary reactance goes to zero, at which point the radiation resistance will be below 73 ohm.
Indeed you are right... the ideal, infinitely thin, dipole impedance at L/2 is ~73+42.5j; you can get it to resonate at a slightly smaller length, where the impedance will be ~70R+0j
Thanks a lot.
Can you use the simulation software to characterize the primary and secondary coils of a Tesla coil?
interesting, btw what would be the best way to simulate a MOSFET with a model you wrote based on a datasheet?
No doubt pigeons on the aerial can be measured with a Bird throughline.
Just curious. I've tried to replicate the LTspice model, but R1 is always generated in the netlist before "subckt" block (independent of the block positioning) and the program can not find the definition. Is there an extra requirement in settings or something else to implement such a frequency dependant model?
The same happens in my case as well, the resistor is first; however, its not a "resistor" but rather a subcircuit - the resistor component is set to be of "X" type - Ctrl+Right click on the component and set the prefix to "x". Let me know if it works out.
@@FesZElectronics Thanks.
i am a materials scientist, and was wondering the state of antenna research now. do you have any insights on the materials aspect? Do you need a more conductive material? A material with variable impedance or capacitance? hehe thanks
For materials, we are interested in permeability and permitivity. Less resistance is always welcome.
Then check "Machining and Microwaves" videos "Unveiling the future of antennas" and "how microwave lenses really work"
Next time model antenna with pigeons plz 😂