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A pure delay (e.g. an ideal delay line) shows as frequency dependent phase shift in the frequency domain but doesn't affect the magnitude. In complex signal math, the delay is represented by a rotation operation: H(jw) = exp(-jωT)
Consider original point of this thread. Decibel definition should be db20() not db10() for this thread point. For example, consider S-parameter of Touchstone format There are following three styles for complex value. (1) dB/Angle (2) Mag/Angle (3) Real/Imag Here Mag=10^(dB/20)
when analyzing the vector of a power source into an AC grid with other power sources, the inverse impedance or Admittance matrix is used to,analyze the power transferred. When a single source is compared with the complex impedance load, the real and imaginary (or reactive power) can be expected, calculated and measured, the latter which is rated i
Your expression for Vout/Vin is NOT correct. At first, R2 (not R) appears in the numerator. But more important: The transfer function is complex - thus, you must apply complex calculations for finding the magnitude and phase.
"replacing s by jw provides the transfer function for physical frequency w, that is, the transmission magnitude and phase for a sinusoidal input signal of freqency w" i could some how understand it ambiguously, but cannot prove it by myself. The complex frequency variable s=sigma+jw is used primarily to compute an
I have two situations: 1) I am trying to calculate the "Total SAR" inside a solid sphere with known mass. I am first integrating Local SAR over the sphere: Scl : Integrate(Volume(Sphere_1), LocalSAR) 2) I am trying to calculate the average value of the complex magnitude of the E-Field along: a) a 2D line b) a 3D volume
there may be systems with good PM as 60degress, and bad GM as 3dB(because of RHZ after UGB. The well-known design rules like 60 degree phase margin for no overshoot in transient response are valid for low-pass loop gain characteristic with a dominant pole. For more complex transfer functions with arbitrary magnitude and phase respo
If you measure loop gain in small signal analysis, you'll see that the barkausen criterion (complex loop gain = unitity) is met for C = about 2.01 pF. For larger C, loop gain magnitude is > 1 at zero phase. The unusual point is that the loop gain is rising versus frequency (at least in the applied measurement configuration). In Nyquist diagram,
The second magnitude/phase diagram is apparently showing a closed loop transfer characteristic. Although the closed loop can be derived from the open loop frequency characteristic, the phase hasn't the meaning of a phase margin. What do you exactly want to compare? The general expression of the (complex) closed loop transfer characterictic Acl o
You can excite with an AC voltage source and measure the current or use a current source and measure the voltage. then you know that: V/I = Z = R/ (1+ jwRC) that is the impedance of the RC circuit. w = 2* pi * frequency Take into account that V, I and Z are complex numbers. So you have to measure magnitude and phase. Calculate V/I from your measur
Impedance is for AC what resistance is for DC circuits. It relates I versus V. That is I=V/R. The difference is that in AC circuits you have to take in account magnitude and phase so the impedance is now represented by a a complex number instead of a real number for resistance.
Yes, they are basically the same idea but there are huge differences also. In a phasor representation we try to represent a wave by its magnitude and phase, which essentially translates into a complex number in an Argand plane. So 100 Exp would be a vector having magnitude 100 and phase (- w t). This is particularly helpful in linear system
To measure a resistance respecticely a complex impedance in a simulator, I'll inject a current into the node and measure the voltage. But all other methods would work in AC analysis as well. The only important point is to achieve correct DC bias without introducing AC feedback or circuit loading.
The |Z| plot mainly suggests an unsuitable measurement setup or broken impedance meter. To determine L and reasonable frequency range for the measurement, you should rather a show complex impedance or magnitude/phase plot. Before impedance and LCR meters have been become popular, people used to determine complex impedances with a (...)
Hello, I have the following Fourier complex signal: v(t) = 2/πsin(500πt)+1/2sin(1000πt)+1/3sin(1500πt) I need to find the minimum sampling rate for this signal. So, according to the Nyquist Theorem, the sampling rate must be twice the highest frequency component contained in the original signal. So I assume my sampling r
If VCO is a complex signal vector then by simple math mag(VCO) is the instantanious magnitude of the complex signal vector and real(VCO) is the real part of the complex signal vector. Now if you were to look at the spectrum of the complex signal VCO you would see several tunes, each being a vector at the (...)
The most logical way is to inject a current into the device and to simulate the voltage across it (ac simulation). If you choose 1 Ampere then the complex voltage is identical to the complex impedance (X=V/I). Now you have the choice to display magnitude and/or phase as function of the frequency or the locus curve in the (...)
What's your particular problem? No arithmetic needed, just connect an AC current source, measure voltage. Different representations (magnitude/phase, complex impedance) can be selected in the plot window.
A Chebyshev type I filter has only poles, one real and a complex pair in case of 3rd order. Your simplified assumption about relation of poles/zeros and magnitude characteristic doesn't aplly to complex pole pairs, I think.
you know something about complex gaussian distributed frequency response? If I have 9 subcarrier,'n', and 3 users,'k', how can I obtain the magnitude |Hk,n|? means, the channel response of user k on subcarrier n.. I hope someone can help me.
The impulse response of the channel is transformed in the frequency domain as summation of complex exponentials in the frequency domain, the magnitude spectrum has spectral peaks that are quasi-constant over a minimum band that is the inverse of the maximum delay (delay spread), the same for the phase spectrum where it is linear only in such band.
I'm not sure but I don't think you can use complex impedance for the discrete port. Maybe just take the magnitude of impedance? Z = R +jX ... since you have a positive value, you are dealing with an inductive reactance. |Z| = sqrt( R^2 + X^2 ) = 151.55 Ohms. Or use lumped components in the 3D model... Or use the 50 ohm port and then use the PSpi
Technically, the fence does not "cause" interference, as in generating unwanted frequencies out of thin air. What it can do is reflect energy off of it. The phase angle and magnitude of that reflection can vary dramatically with a small frequency change. So if you are trying to send a widband signal with some sort of complex modulation format, a
Yes, it's not easy - however, rather straightforward. Use the complex transfer function (2nd order) and calculate the magnitude. Then, set the magnitude equal to 1/sqrt(2) and solve for w. But I do not recommend this procedure cause you will learn not too much. Therefore, the normal and classical approach is to use tables in textbooks (...)
Hi dBmd, neglecting the up-to-now-discussion I like to answer your original question as follows: When doing a bode magnitude plot for a complex pole, do I use the real or img part of the pole ? Matlab seems to point to the img part (20), which is confusing since for the non-complex pole, the real part (1) is used. tf=1/((s+1)*(s^2+s+400) U
Hey guys..need some help with MATLAB. I want to draw a graph of magnitude of (40*cos(x) + i*54.77*sin(x))/(54.77*cos(x) + i*40*sin(x)) where x is x=0:pi/20:4*pi; I am just getting a graph for single value and not the complete x domain. Can you help me here? Please find the attached file for graphs of numerator and denominator seperate
What's the influence of complex poles to OP-amp stability? In "CMOS Analog Circuit Design 2nd Edition" by Phillip Allen, he pointed out that the complex poles may result in poor phase margin in section 7.1, more specifically Figure 7.1-5(a). Can anyone tell me why the poles p2 and p3 in Figure 7.1-5(a) is bad for PM or recommend some paper whic
Power spectral density is the quantity you display in a power spectrum or spectrogram, there's no difference. Basically, a power spectrum is the magnitude part of a the complex fourier transform output. You can use MatLab to calculate it, or even a spreadsheet calculator like MS Excel.
Hello, I need to decide if to apply a "sophisticated" error correction for power ratios to a given system or to use something simple for power detection. The problem is when apply the six terms error correction. Hence, I woul like to ask if the values of those terms are complex numbers (magnitude and phase)? The Agilen Application Note 128
sinc3 vs cic: guess it is a trade-off between complexity and performance. More complex -> better image removal and vice versa. slope to magnitude: all these filters do are just averaging. More complex filters given you average of the averages many times over. Now finding the average is just integration, if you ignore (...)
Hello! I'm working on a thesis about Speech noise reduction in Matlab. Basicly these are the steps Im following: 1.Read oiriginal signal 2.Add Gausian noise 3.Frame sampling 4.complex Spectogram 5.magnitude Filtering (Using a bilateral Filter) 6.Reconstruction(IFFT,Overlap resynthesized frames,Normalized resynthesized frames) But the r
You can use the fields calculator to calcuate the complex current and then knowing the magnitude and phase of the voltage you can calculate the impedance. I have been trying to do this with a dipole my self. Our set ups sound similar but I am just using a voltage source between the two cylinders and then measuring the current right at the center of
hi. if i get a complex impedance of a microstrip trace, then what is the impedance really? the real part, or the magnitude? for terminating a microstrip line. normally done by a resistor. i just did some EM simulation, then calculations on the results, and it says: z0=67.36+j*64.8 ohm. magnitude is 93.42 if i calculate the (...)
S-parameter is complex (magnitude and phase) so it cotains more information than the power ratio. In any case, even if you define it as a RATIO of two powers, it doesn't have the unit of power. 10Log is incorrect.
There is a specific method to increase FFT resource utilization by using real and imaginary part, but as a first step, it's easier to simply zero the imaginary input part. Furthermore, a window function is usually needed when the FFT of a signal cutting is to be analyzed. And a magnitude should be calculated from complex FFT output.
Hello everybody, I have some questions about signal type setting in simulink: (1)?Real? and ?complex?, which type should I use? What?s the difference between them? (2)If I set the signal type to ?complex?, whether I should add a ?complex to magnitude-angle? module to see the output spectrum? The detailed descripsion (...)
Convert your ADC's real data into complex format by simply setting the imaginary parts to zero. Then feed that into the FFT.
For RHP zero LHP pole doublets: peak ac magnitude and 180 degrees in phase For complex poles: the same as doublets. How to distinguish the pole-zero doublet or complex pole in the bode plot as pic shown
Hi, WinglJ: Field quantity is a complex value (c = re + j im ), absolute value of a complex value is |c| = sqrt( re*re + im * im ). Regards.
The fft() returns an array of complex values. A complex value tells you magnitude and phase. The abs() function extracts the magnitude (amplitude) and discards the phase. That's what you want for an ordinary spectrum plot. If you wish to display the magnitude in decibels rather than linear units, then you (...)
hi i m cofused in some Question as in previous post , yet not cleared.... i m posting some of my results(pics) of the above code , plz try download it and try to explain me from these ........ 1) first the original signal in text form ,i read it in matlab 2) The FFt of the origial signal ( This gives a complex plane) 3) why we need Ab
It sometimes depends on who's FFT function you are using. Here is a MATLAB example. Notice the fs/N and 2/N. If you are unfamiliar with MATLAB, the abs() function returns the magnitude of a complex number. N = 64; % number of points fs = 4000; % sample rate f1 = 750; % signal 1 frequency f2 = 1000; % signal 2 f
Yes, but you are not averaging correctly. You must treat the complex number has a whole, not interpolate the magnitude and angle separately: 1/2* = 0.651*e^(-j*52.9*deg) You can also break it into real and imaginary parts, interpolate those separately, and get the same result.
I am working on a complex filter for wireless communication, 6-stage, biquards structure, for ideal inputs, the outputs is good enough. the image suppression (-2M Hz) is 70dB, but when mismatch occurs in the inputs (0.3dB in magnitude and 1° in phase), the image suppression have reduced to 34dB,(what i need in 35dB at least) which was run in TT cas
hi, i want to find the peak value of the given input 2048-point complex data, please give me the algorithm or verilog code for this...
That question is bad! There is no "n" variable. a = 0.88 * exp( j*2*pi/5 ); % This is a complex number nn = 0:40; % This is an array xn = a.^nn; % "xn" is a Complx # raised to a power "nn" for n = 128. % this looks like it wants to be a loop w/128 i
hi, as of such, there are no rules that say the contant shouldnt be a complex number. complex numbers only convey more information abt a signal( for that matter) which has in addition to the magnitude in ordinary numbers, the phase content of the signal. And u would know it can again be represented in the magnitude phase (...)
Of course the permittivty is a complex number and thus has magnitude and phase, so one should be careful in extracting this value. Of course a piece of equipment called the Thermal Mechanical Analyzer (TMA) with the electrical option will measure a sample's complex permittivty as a function of frequency directly, but unfortunately this piece (...)