Recent content by squalho

hotvette, Thanks for the answer. However, it doesn't seem to me that the problem can be easily linearized. My problem is to find the values of A, phi and alpha. If I used a Taylor series expansion I would end up dividing my problem in many linear interpolators, each one working over a subset...

Fitting points to "skewed" sinusoids Hello, I have a problem related to least square fit of data. Let me start from a step back. I have a set of points, given as x-y coordinates. x represents an angle and y the corresponding value of a function. I am fitting sinusoids to those data points...

Hello, I have a question related to coordinate transform. If this is not the right section please feel free to move this thread. My problem is the following: I have a positioning system to move an antenna, that allows me to perform scans according to a great circle coordinate system. Check...

I understand the antenna factor relationship, but I don't think it's what I'm looking for. First of all, that relation involves AF (suppose I know it from the manufacturer), E (what I want to find) and V (voltage at the output of the antenna). So none of that information is something that I...

Thanks everybody for your answers. Addressing them one by one: sophiecentaur: what do you mean with caracterize/calibrate the antennas? I can calibrate the cables up to the last connection before the antenna, but I don't think that's what you mean. Can you be more specific? waht: I have a...

Hello, This is my problem: I have a network analyzer, that is capable of measuring the S-parameters of a 2 ports network. Let's say that I connect antenna #1 (a standard half-wavelength dipole) to port #1 of the NA, and antenna #2 (same type of dipole) to port #2 of the network analyzer...

I'm sorry, when you mentioned 3dB beamwidth I thought you knew already everything :) Long story story short: I have an array with N elements. If you try to plot that function (1/N sin(Nx)/sin(x)), for x going from 0 to 2pi in polar coordinates (or cartesian, for what matters), you see that...

In order to use low order approximation I must suppose that the argument of the sine is low (Jason mentioned somewhere between 0 and pi/N). But the argument of the sine is not small, can be anything from 0 to 2pi

Jason, You are right, I have an antenna array type of problem. I also feared that there wasn't an analytical solution. I'm basically interested in knowing where the main beams are. Without making any assumption I can have one or more, and oriented in any direction. What I'd like to have is...

Hello, I have been an avid reader of the physics forum, and now I think I finally have something worth asking. The problem is engineering-related, but it all comes down to a trigonometric equation, so I'm posting in general math. The problem is the following: \frac{1}{N^2}...