Gregpaskal: Created page with "{{: Header_Nav}} == Overview == * An RF signal or wave radiates away from an antenna (often in a wireless access point) in a continuous pattern that is governed by properties such as wavelength, frequency, amplitude, and phase. However, the signal’s movement and behavior are also affected by other components such as absorption, reflection, scattering, refraction, diffraction, free space path loss, attenuation, and gain. * The radio spectrum is from the upper limit of..."

2025-04-05T03:44:55Z

Created page with "{{: Header_Nav}} == Overview == * An RF signal or wave radiates away from an antenna (often in a wireless access point) in a continuous pattern that is governed by properties such as wavelength, frequency, amplitude, and phase. However, the signal’s movement and behavior are also affected by other components such as absorption, reflection, scattering, refraction, diffraction, free space path loss, attenuation, and gain. * The radio spectrum is from the upper limit of..."

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== Overview ==
* An RF signal or wave radiates away from an antenna (often in a wireless access point) in a continuous pattern that is governed by properties such as wavelength, frequency, amplitude, and phase. However, the signal’s movement and behavior are also affected by other components such as absorption, reflection, scattering, refraction, diffraction, free space path loss, attenuation, and gain.

* The radio spectrum is from the upper limit of audio frequencies to the lower limit of infrared. It is generally considered to be from 3Hz (ELF) to 300GHz (EHF), with frequencies above 1 GHz considered microwave.

== Reference ==
* [https://www.extremenetworks.com/resources/blogs/2023/04/28/20/09/do-you-know-the-rf-fundamentals?utm_campaign=23_Wi-Fi_New-Website-Traffic_0000_CORP_AMS_PSH_BLG_WW_EN_GA_do-you-know-the-rf-fundamentals&utm_medium=cpc&utm_source=google&utm_content=do-you-k Do you know RF fundementals]

* [https://www.extremenetworks.com/resources/blogs/how-are-rf-signals-transmitted-lets-talk-equipment?utm_campaign=23_Wi-Fi_New-Website-Traffic_0000_CORP_AMS_PSH_BLG_WW_EN_GA_how-are-rf-signals-transmitted-lets-talk-equipment&utm_medium=cpc&utm_source=google How are RF Signals Transmitted]

* [https://terasense.com/terahertz-technology/radio-frequency-bands/ Radio Frequency Bands]

* [https://www.hackster.io/news/long-range-wifi-for-the-esp32-9429ab89f450 Long-Range WiFi for the ESP32]

* [https://www.youtube.com/watch?v=2rujjTOPIRU External antennas and ESP32 Long-Range mode]
* [https://www.youtube.com/watch?v=PUppoaePi3A External antennas and ESP32 Long-Range mode (continued)]

== Definitions ==
* Absorption: most materials will absorb some amount of RF signal as it is traveling between the antenna and the user device. Drywall absorbs a relatively small amount of signal while brick or concrete will absorb a significant amount of signal.

* Free space path loss: RF signals spread out naturally as they move away from an antenna, and as a result the strength of the signal attenuates (decreases).

* Gain: the amplification of an RF signal.

* Propagation Behaviors: The way radio signals are affected by different materials it travels through. Reflection, scattering, refraction, & diffraction: these are all RF propagation behaviors that cause an RF signal to travel in a different direction than it was originally intended.

* Signal-to-noise ratio (SNR): The difference between the received signal and the background noise level. Data transmissions can become corrupted with a very low SNR which means your communication or data transfer will not work very well.

* Receive sensitivity: The power level of an RF signal required to be successfully received by the receiver radio. The lower the power level that the receiver can successfully process, the better the receive sensitivity.

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RF - Revision history