Recent content by csopi

Many thanks! I have looked into phase noise, and now I understand that I should calculate the total rms phase error, which describes the "average" deviation of the system. And here comes the problem: how to calculate this? I have found various tutorials on manufacturers' website, most of them is...

Hi, I have a roughly 1.1 GHz signal to be downconverted to 100 MHz by mixing it with a 1 GHz local oscillator. I am not sure how to choose the performance of the LO. In particular: let's assume the LO has a jitter of 100 fs rms. At 1 GHz this corresponds to a frequency error of 100 kHz. Does...

Thanks for the immediate reply! I have heard about this one, actually already tried a basic version. I am wondering if there are other methods? B & B is an "art" for me, not sure what is the most efficient way for bound estimation, that's why I am asking.

Hi, I have the following optimization problem. I have a list of tasks that I should be able to perform with my tools. Each tool costs a certain amount of money, and may be used to carry out a finite number of tasks. The goal is to choose an optimal set of tools in such a way that the toolset can...

Hi, let's say I want to measure the frequency f of a periodic signal. I may take N data points with an arbitrary timestep of T. The question is how shall I choose T for a fixed N to have the best accuracy? In principle the frequency resolution is 1/(N*T) when taking the Fourier transform...

First you should solve the equation for 'a'. After that, you can calculate the argumentum and the abs. value of 'a', resulting in a = r*(cos(theta) + i* sin(theta)). Finally, apply De Moivre for calculating a^2011.

Hi all, I am wondering about the actual technological parameters of a modern MRI. In particular I mean sensitivity, i.e. the order of magnitude of the signals to be detected and the noise levels in practice. Can somebody recommend a good reference about the subject from an engineering...

You have thought it right, 'A' can be complex indeed. In fact, A=\sqrt\frac 2 a\,e^{i\phi} satisfies the the normalization constraint for any real \phi. Mind that the phase of the wave function is arbitrary.

Good idea, but unfortunatelly this won't solve my problem. I'll use it as a sample holder at 4 K, and it'll be subjected to AC magnetic fields. The aim is to get rid of the eddy currents and for this I need the bulk to be an insulator as well.

Thank you very much for your help, I'll look into the hints!

Hi, Does anybody know a material which is a good thermal conductor and an insulator at the same time (at temperatures around 4 K) and is "easy" to fabricate? For e.g. sapphire fulfils the first two requirements, but is extrmely hard.

Here are some crucial differences: 1. A Laurent series is convergent on an annulus in the complex plane, whereas the Taylor series is on a disk. 2. EVERY function that is holomorphic on r < | z - a | < R has a unique, convergent Laurent series (defined on this disk. The exact values of the...

Here are some crucial differences: 1. A Laurent series is convergent on an annulus in the complex plane, whereas the Taylor series is on a disk. 2. EVERY function that is holomorphic on r < | z - a | < R has a unique, convergent Laurent series (defined on this disk. The exact values of the...

Thank you, I'll look into it! Just out of curiosity: do you know any open source alternative?

Hi all, I need a proper software for designing microwave cavities. I intend to use simple base geometries (e.g. closed box) with some modifications, like holes for optical access or for feeding the MW. These modifications however may seriously affect the Q factor, the frequency or might...