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Hello,
if we measure antennas in the antenna chamber with vector-network-analyzer (VNA).
Let's say two identical antennas:
The measured S21 transmission parameter (divided by 2 and corrected...

True, so Volker you agree with streamlet.
Fine for me, thank you all very much!
Even if it the answer from support was different...
-e

Mag_E = ComplexMag_E * cos(Phase)[/QUOTE]

Hi, but then the CmplxMag result should be identical to at least one MagE result, but this is not the case ?!
-e

Thank you.
Ansys answered: magE=magnitude of complex number, cmplxMagE=averaged over all phases

E(x,y,z,t) = Epeak(x,y,z) * cos[wt + phi(x,y,z)]
I guess HFSS is using Epeak(x,y,z) in case of magE. Using animation the cos-term is multiplied.
Does anybody know the difference to cmplxE. In the...

Hello,
just to be sure, could someone comment on the difference between magE and cmplxE in HFSS.
Thank you very much.
Best regards
-e

Hello, as straight waveguides should have linear dependency between transmission S21 phase and frequency, and group delay is the derivative of transmission phase with respect to frequency, why is...

Thank you very much. Sometimes the basic stuff gives me a headache ;)

... to be a little bit more precise:
Using S11(f) expressions of a transmission line with characteristic impedance ZW and termination impedances ZT, we can see 20*log10( abs(S11(f))) having maxima...

Hi guys,
very basic questions: How do we explain the minima/maxima of S11 versus frequency, e.g. of a transmission line.
Thank you very much.
-e

Hi,
cross range resolution of synthetic aperture radar is independent of frequency and range.
How can this be ?
Cross range resolution of 2d multistatic imaging arrays is proportional to range...

Dear juppydu,
boresight means CST will use the main field component that is alligned to the theta (elevation) direction - should be fine for our setup.
We use +/-15 degree=30 degree around the main...

Dear juppydu,
I will try to find out what is going on and discuss these things internally first.
I come back to you next week. Thank you very much for your time and comments.
-e

Hello juppydu,
normally I use HFSS, but I found the angular range (see pic). It is 30 deg around direction of propagation. This should be fine, no side lobes included.

...

Thanks.
@Terminator3: Other simulations from 75 to 110 GHz (mono mode operation) give the same results.
@juppydu: Calculationof CoP is done by CST. Angular range is not a parameter, but...

http://obrazki.elektroda.pl/9190117900_1495439735_thumb.jpg

It is not a phase shift, it is the phase_center in x-direction versus frequency. Dimensions=milli-meter.
x-direction, is also the direction of propagation. The phase center is located in the center...

Hi,
attached is the result of a 3D simulation with CST time domain solver (FIT).
The phase center (coordinate=direction of propagation) of an open waveguide (WR10, W-band).
If you want to use the...

Ok. For the sense of completeness, we think the reason for LDO failure is reverse current flow. When turning off the input voltage, the output capacitor is fully charged and forces a reverse current....

Hi biff44, well phase center acutally does change with frequency.
This is pretty much a problem if antennas are part of distance sensors or tracking/imaging sensors.
I am just wondering why the...

Hello FvM, ok. I think this type of problem is difficult to solve with forums. It was worth trying ... Lets mark it as solved and close it here. -e.

Hi,
I am calculating the phase center of horn antennas and open waveguides (WR10, W-band).
It seems, the phase center is centered within the aperture and first moves backward with frequency....

Ok. I think we wont solve this problem here.
I will try it with a new post and correct headline!

Hello again,

thank you for your replies.
This seems to be a big problem for many of my modules, hence I would like to share more data.

@schmitt trigger:
Due to the current compliance of the...

Hi guys,
we use an array of 20 linear voltage regulators (LDOs) with 5.5 Volts at the input. Each LDO has a 10uF SMD capacitor to ground in 0402 or 0602 size.
After assemby, the DC input...