89
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 08 Jun 2024
89 points (95.9% liked)
Ask Science
8465 readers
97 users here now
Ask a science question, get a science answer.
Community Rules
Rule 1: Be respectful and inclusive.
Treat others with respect, and maintain a positive atmosphere.
Rule 2: No harassment, hate speech, bigotry, or trolling.
Avoid any form of harassment, hate speech, bigotry, or offensive behavior.
Rule 3: Engage in constructive discussions.
Contribute to meaningful and constructive discussions that enhance scientific understanding.
Rule 4: No AI-generated answers.
Strictly prohibit the use of AI-generated answers. Providing answers generated by AI systems is not allowed and may result in a ban.
Rule 5: Follow guidelines and moderators' instructions.
Adhere to community guidelines and comply with instructions given by moderators.
Rule 6: Use appropriate language and tone.
Communicate using suitable language and maintain a professional and respectful tone.
Rule 7: Report violations.
Report any violations of the community rules to the moderators for appropriate action.
Rule 8: Foster a continuous learning environment.
Encourage a continuous learning environment where members can share knowledge and engage in scientific discussions.
Rule 9: Source required for answers.
Provide credible sources for answers. Failure to include a source may result in the removal of the answer to ensure information reliability.
By adhering to these rules, we create a welcoming and informative environment where science-related questions receive accurate and credible answers. Thank you for your cooperation in making the Ask Science community a valuable resource for scientific knowledge.
We retain the discretion to modify the rules as we deem necessary.
founded 1 year ago
MODERATORS
Sorry, your comment doesn't make sense and doesn't seem correct to me.
Yes there is a capacitance, but capacitance isn't "voltage potential". Capacitance is a ratio of coulombs per volt. Anyway, that's beside the point.
There is capacitance and it's defined by geometry.
"The potential between you and the antenna affects the filter of the signal"
You're not adding potential to anything, nor are you affecting any filters.
Any capacitance you add will change the impedance of the resonant antenna. You get maximum power transfer when the impedance is matched.
Another way to look at it, you're changing the resonant frequency.
How do you think you are changing the resonant frequency? By modifying it's capacitive impedence, i.e. creating a capacitor with yourself and the antenna.
And you know what we call the difference of electric potential between two points? Voltage.
When you say that capacitance is geometry, you are right. The distance between two objects, be it you and an antenna or two planks of wood, affect the capacitive impedance.
... Was this written by ai
I'm an rf engineer and I swear it feels like I'm having a stroke reading your comments
As the distance increase between two surfaces, the capacitance diminishes and the voltage between the two increase, so that C=QV is always true.
The resonant frequency is determined by the impedence, i.e. capacitive and inductive impedence.
You can't affect inductive impedance of the antenna because you are not a coil and do not emit EMR. But you can change the capacitance between you and the antenna by moving closer or further away.
as the distance increases the capacitance reduces. But C=Q/V doesn't mean you're not inducing any potential into the antenna... You're adding to the load... C=ε*A/d is the equation that says capacitance will decrease with distance, but that isn't going to induce any voltage in this case.
yes this is what I'm saying.
in the very near field, conductive tissue, ie a body, will have Eddy currents. Your body has an ε term as well as σ. You can definitely load an antenna. The R term will dominate but there will be some effect on inductance.