# Antenna, transmission line

1. Sep 8, 2004

### Mica

Hi,

I want to clarify some notiona in an antenna. The major components of an antenna are a generator, transmission line and an antenna (dipole). Let's say the whole system has a perfect matche, i.e. the dipole is about 70 ohms as the transmission line. If my generator ,the output voltage, is an impulse which has a duration in a micro second ( let's say 1 micro sec). So, the frequency of this generator is 1 Mhz? If the impluse is a square, the main fundamental frequency is 1 MHz and also , with others harmonics, I means if I do the Fourier Transformation am I right?

Thanks,

Mica

2. Sep 8, 2004

### chroot

Staff Emeritus
A square wave is composed of odd integer harmonics. The third, fifth, seventh, and higher order odd harmonics all have power in them.

- Warren

3. Sep 8, 2004

### Mica

How can I determined these odd integer harmonics ? and if is another wave form ? And the calculation of the power of these harmonics ?

Thanks,

Mica

Last edited: Sep 8, 2004
4. Sep 8, 2004

### chroot

Staff Emeritus
http://mathworld.wolfram.com/FourierSeriesSquareWave.html

Look at equation 6.

The third harmonic has a frequency three times that of fundamental, and has an amplitude one-third that of the fundamental. The fifth harmonic has a frequency five times that of the fundamental and an amplitude one-fifth that of the fundamental.

- Warren

5. Sep 9, 2004

### Mica

Thanks for the information. So, for my dipole radited efficiently, I just match the right frequency output of the generator ? I mean like if my dipole resonances at 1 GHz so, my impluse (voltage source) duration will be 1/1 GHz ( 1 nano second) independent of the wave form?

Mica