btb4198 said:If I use this one http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=11_45_47&products_id=169,
I would get
Received Power: 9.433e-9 mW
but I do not know if that is good or not.
btb4198 said:wait I get
Received Power: 3.396e-7 mW
not sure where that last number came from
Frequency 900 MHzthe_emi_guy said:If you are getting 3.3e-7mW a mile away from your transmitter, it must be a really powerful transmitter.
Maybe you should share the inputs that you are supplying to the Friis equation.
BTW dBm is 10log(milliwatts)
What is the antenna gain or aperture?btb4198 said:Frequency 900 MHz
Gain 5 dBi
Max. Power 50mW
I used this site :
https://www.pasternack.com/t-calculator-friis.aspx
the gain for the Tx is the same for the Rx because I am using the same antenna for both.
https://en.wikipedia.org/wiki/Antenna_gaintech99 said:What is the antenna gain or aperture?
Sorry, I meant antenna gain in your case, so I can look at the calcs.the_emi_guy said:
Good Friis Transmission (GFT) is a formula used to calculate the signal strength between a transmitter and receiver in wireless communication systems.
GFT is calculated by using the transmitter power, antenna gains, distance between the transmitter and receiver, and the frequency of the signal. The formula is GFT = Pt * Gt * Gr * (λ/4πR)^2 where Pt is the transmitter power, Gt and Gr are the transmitter and receiver antenna gains, λ is the wavelength of the signal, and R is the distance between the transmitter and receiver.
GFT allows for the prediction of signal strength in wireless communication systems, which can help in the design and optimization of these systems. It also takes into account factors such as antenna gain and distance, which can greatly affect signal strength.
Yes, GFT is based on theoretical assumptions and may not always accurately reflect real-world conditions. It also does not take into account factors such as obstacles or interference that may affect signal strength.
GFT results can be used to determine the feasibility of a wireless communication system and to optimize its design. It can also be used to troubleshoot issues with signal strength and to predict the coverage area of a system.