Microstrip dipole anternnas as coupled microstrips...

[amal banerjee]

Could some electronics guru here please clarify this a bit.
As a microstrip is a transmission line, can a half wavelength dipole antenna be modeled as two transmission lines, each of physical length wavelength/4, coupled
capacitively? The free ends of each microstrip drive
free space impedances(377 Ohm) each, whereas the other
end of one is connected to the signal source, and the
other microstrip has one end grounded. Any flaws in this reasoning ?

 

[Leo Baumann]

Am 30.09.2020 um 16:18 schrieb Leo Baumann:

and then calculate the effective epsiolon_r for 2nd shortening
with PCB Toolkit from internet.

 

[Leo Baumann]

Am 30.09.2020 um 16:19 schrieb Leo Baumann:
1.) Balanis/Dipol/vakuum -> lenght1
2.) lenght=lenght1/sqrt(epsilon_r_effective)

 

[Leo Baumann]

Am 30.09.2020 um 13:57 schrieb amal banerjee:

Could some electronics guru here please clarify this a bit.
As a microstrip is a transmission line, can a half wavelength dipole antenna be modeled as two transmission lines, each of physical length wavelength/4, coupled
capacitively? The free ends of each microstrip drive
free space impedances(377 Ohm) each, whereas the other
end of one is connected to the signal source, and the
other microstrip has one end grounded. Any flaws in this reasoning ?

You need a balun for driving the symmetrical antenna and Lambda/2 is too
long. Also You need the effective epsilon_r to shorten 2nd time of You
constellation.

Use Balanis/Dipol for a first lenght, and then calculate the effective
epsiolon_r for 2nd shortening.

www.leobaumann.de/usaantennenimpedanz.htm

 

[Leo Baumann]

The balun You will find here

www.leobaumann.de/down.htm#boucherotbruecke

have fun

 

[amal banerjee]

On Wednesday, September 30, 2020 at 8:29:26 PM UTC+5:30, Leo Baumann wrote:

The balun You will find here

www.leobaumann.de/down.htm#boucherotbruecke

have fun

Thanks a lot for the very helpful point about impedance matching with the balun.
since the two microstrip dipole arms must have 180 degree out of phase current in them. Somehow I had missed it initially.

 

[Leo Baumann]

Am 01.10.2020 um 13:37 schrieb amal banerjee:

On Wednesday, September 30, 2020 at 8:29:26 PM UTC+5:30, Leo Baumann wrote:
The balun You will find here

www.leobaumann.de/down.htm#boucherotbruecke

have fun

Thanks a lot for the very helpful point about impedance matching with the balun.
since the two microstrip dipole arms must have 180 degree out of phase current in them. Somehow I had missed it initially.

w is 2*PI*f here