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| wirelessboy 2003-04-03, 11:46 am |
| Which statements are NOT true about antennas
A. The antenna and the signal must have same polarisation
B. High-Gain Antennas are directional antennas
C. Antenas work because of skin effect
D. Antennas should result in high value of VSWR
E. The size of the antenna is related to amplitude of the wave. | |
| yeskay 2003-04-03, 12:30 pm |
| My answer is A. Polarization is electromagnetic field relative to the earth. when you say signal it relates to freq, ampl, wave-length etc. | |
| wirelessboy 2003-04-04, 7:26 pm |
| i am not too sure
some expert might reply .
i was thinking of D and E
D. VSWR should be as less as possible
E. Size related to Frequency
regards | |
| Evilphil 2003-04-05, 8:46 am |
| The impedence of the antenna must match as well. ALL components in a system must have the same impedence to avoid VSWR.
I'm not too sure about the amplitude of the wave being directly related to the antenna size. I do know that for an antenna to work properly, you have to take into account the wavelength being propagated.
Hence the pringles can antennas. The front collector is directly related to the size of the wavelength. If you double the size of the collector, you effectively increase your dB gain. In doing so, I would assume that the amplitude would get larger. But don't quote me.
http://www.oreillynet.com/cs/weblog/view/wlg/448 | |
| kkchan0 2003-04-14, 12:57 pm |
| Which statements are NOT true about antennas
A. The antenna and the signal must have same polarisation
B. High-Gain Antennas are directional antennas
C. Antenas work because of skin effect
D. Antennas should result in high value of VSWR
E. The size of the antenna is related to amplitude of the wave.
Is that Antenna work because of skin effect?
can anyone explain what is skin effect briefly? | |
| meijin 2003-04-14, 3:00 pm |
| Skin effect is the tendency of an electrical current to pass through the outer portin or "skin" of a metallic conductor rather than the center and is a phenomenon associated with high frequency signals (above 50 KHz). The higher the frequency the greater the effect. | |
| kkchan0 2003-04-14, 10:42 pm |
| That means Antenna works because of skin effect or not?
Thx!!! | |
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