All Questions
7
questions
1
vote
3
answers
606
views
What is the difference between antenna input impedance and its radiation resistance?
I got to know that the input impedance of the halfwave dipole antenna is given as:
$Z_{in}$=1/$I_m$* sin($\beta$(H-|Z|))
where $I_m$ is the maximum current on the antenna( when excited with a 1 volt ...
- 99
5
votes
4
answers
2k
views
Does a receiving antenna radiate the power received?
Let's consider the case of linear dipole antenna or Hertz dipole.
I know that the antenna acts as a transducer and it radiates the E-M waves due to the acceleration and decelaration of the electrons ...
- 99
0
votes
0
answers
56
views
What is the gain of an isotropic antenna?
My question is simple:
What is the gain of an isotropic antenna in dBi?
I cannot find a consistent answer on the internet. Some sources define it to be 0dBi and others define it to be 1dBi.
Thanks.
2
votes
1
answer
209
views
Derivation of the Gaussian Beam Pattern
I am currently reading this book by Mireille Levy. It says (on page 40) that the Gaussian beam pattern with half-power beamwidth $\beta$ is gien by:
$$B(\theta)=A\text{exp}\left(-2\text{log}2\frac{\...
- 177
0
votes
1
answer
26
views
Radiation EIRP impact on organisms
I read some documentation about how harmless the non ionizing radiation can be and it looks like the arguments are around the frequency(hence the energy) of the wave. In the sense that a particle with ...
- 101
1
vote
0
answers
231
views
How to Calculate the total scattered radiation power and total radiation power.?
Let's suppose I have incident field $E^i_z$.
The components of Scattered electric and magnetic field are $E^s_z$, $E^s_\phi$, $H^s_z$ and $H^s_\phi$.
The electric and magnetic field components ...
0
votes
1
answer
155
views
Power spectral density of noise: what is $\mathcal{N_0}$ in $S_X(f)=\mathcal{N_0}/2$?
My question is regarding power spectral density of white gaussian noise. It is known that the power spectral density of white gaussian noise is $$S_X(f)= \frac{\mathcal{N_0}}{2}$$
My question is does ...
- 11