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Hi everyone

Do you know are there any objective Acceptance-Test to verify an antenna measurement system is reliable?

e.g. isolation of the shield chamber > 110 dB, the aligment of the system, ...

Actually, the simulations is very simple, i'm quite sure nothing screwed up because the simulated result are pretty much agree with experiment in term of the resonant frequency (S11 dip).

I maybe m ...

hi everyone,

i'm doing some rf coil, with tuning capacitors, simulations using HFSS. The impedance bandwidth is very very narrow (S11), which is expected. I found that when i changed some minor v ...

Hi All

As far as i know, the relationship between NearField Radiation Pattern and FarField Radiation Pattern is bounded by Fourier Transform.

i.e. NearField --> (FFT) ---> FarField

But ...

Thanks for Admin's reply and i like the statement "gain should be measured as total gain unless specifically stated otherwise".

So for the case of circular polarization antenna, it's eith ...

I've the same experience of having incorrect gain value when using some simulations software.

Of course, i tried to use a simple dipole to test the software but the value is higher than the expecte ...

Yup, Efficiency is great. So we should target for high-efficiency small-antenna instead of high-gain small antenna (assuming we're targeting Omni-pattern, which is always true for small-antenna.)

...

I pretty much understand the performance of such small antenna with multi-pol. And so i realize they are different from those standard-size or large antenna (like base station array) in term of gain. ...

Let say i've a small antenna which usually is a multi-pol antenna with high cross-pol (i.e. say neither pure-vertical nor pure-horizontal pol.) across the bandwidth.

How would you describe the gain ...

Are you talking about L-probe feeding patch antenna? If yes, it's already a wideband design like using U-slot. Try to use air-substrate with thickness about 0.1 lambda.

Bty, so what is your bandw ...

Is the Q-factor important in antenna theory?
What's is defination & equation of Antenna-Q?
Is it Q=fc/(f2-f1)? [fc-center freq, f1 and f2 are cutoff freq]

What i understand is higher the Q ...

So i'm using the IEEE definition. My way to memorize is to let the Thumb be Propagation Direction, and the 4 fingers will be the sense of rotation.

Anyway, thanks and it was a very good discussion ...

Many thanks. Yup, Polarization Loss Factor is one of my interested toipc.

Yr explaination is clear for me, and so i was wrong in my guess in the question above. In case one, it's not 0.6667, it s ...

I made a mistake on the vertival dipole transmitting 1W of power. The power will radiate in all directions, so i can't get back all power even when i use a vertical dipole.

So for the question, an ...

Another question related to circular / elliptical polarization:

What i understand is if i've a Linearly Polarized Antenna, say a vertical dipole, transmitting 1W of signal. Theoretically, I can re ...