lumped matching network in hfss

i am trying to match my antenna by using a lumped matching network.
i fed the antenna using a lambda/12(using fr-4 @2.4ghz)line the thickness of the substrate i used is 3.6 mil and z0=50ohm.
i calculated the dimension using this.(see the link below)

http://www.emtalk.com/mscalc.php?er=...units_list=Lmm.

then i used a lumped port and found the impedance seen by the port using active z (re and im).
my zin=0.05+j33.36.

so to match this to 50 ohm i used a l lumped network where the component value i determined using (see the link below)

http://home.sandiego.edu/~ekim/e194r.../matcher2.html
(used the first ckt)

c=1.894pf and l=0.109nH.

i drew the rlc boundary for capacitor and connected it to previous geometry(tr line of lambda/12 included) the other end of this c boundary is connected to another tr line of same specification.
both tr line have same ground plane.inductor is connected to one end of capacitor boundary and ground to the another.

after doing this when again i used the lumped port to find the zin it gives the same value as previous one.
means it is not matched. but why?

i just extended the the metal and ground of the second line by small value to provide separation between the inductor boundary and second line. but removing this gap also do not helped.getting the same zin.

.

see the images to check the connection of tr_line with the matching networks.

i am using driven model.

new to hfss so don't know whether this much info is enough or not

If the real input impedance of your antenna is actually 0.05 ohm, start with redesigning the antenna. Matching this tiny radiation impedance is a helpless undertaking.

Agreed with FvM on the impedance.

Also, your workflow is inefficient and can introduce user mistake. It will be much easier if you separate the EM simulation task (antenna) from the circuit simulation task (combine S-parameters of antenna and matching network). EM part in HFSS, but the rest in Ansoft designer. Ansys includes Designer with HFSS, so you should have both products available.

sir by redesigning do you mean to change my antenna geometry ?
because i can not do that. will attaching a matched network between tr line(first one) and my antenna geometry will help.
this will change the load impedance seen by the line.

also i have not used ads so can you please tell me what i am actually supposed to do.
find the s parametrs of the antenna using hfss and then use them with the matching network in ads.

thanks for replying

sir,

do you mean that i should find the s parameter of the antenna using hfss.
and then use this in ads along with my matching network.

thanks for replying

zin=0.05+j33.36 has all necessary information to calculate a matching network. But it's effectively impossible to implement useable matching for 1:1000 Re(Z) ratio.

You have apparently designed a structure that doesn't radiate at all, either because it's far too small or it's not suitable as antenna.

If you give as an idea about the geometry, we can better understand what's the problem.

sir
i have a battery which i am supposed to match and somehow make it work as an antenna .
so i assumed a 0.3 mm aluminium on both top and bottom of the cylindrical structure and the substarte(zinc of height 3 mm between those al). both al surfaces and zinc sub have a radius of 11.5mm.
i connected one extended connector of aluminium(0.3 mm thickness and length 4mm) and then used the transmission line to connect to this connector and then found out the zin.


please see the image below

i have connected the top al of battery with the connector using boolean function

sir even if matching is difficult but on attaching the matching network it should change the zin seen,
but even now i am getting the same zin.
as if matching network is not working at all.

i can send my design if that will help.

hii there ia m using a battery (zn substrate h=3mm and radius=11.5mm and aluminium on top and bottom of that of same radius h=0.3mm) and connected it to aluminium surface of width =2mm h=0.3mm and length=4mm.this is connected to upper al surface of the battery. then i am using a lambda/12 line of fr4 substrate (h=3.6 mil @2.4 GHz) of z0=50ohm. see below link.
i am using lumped port for feeding and my input impedance zin=0.05+j33.36. is this correct.
am i doing it right.

i can mail my design or if someone tell how to upload it here i can do that as well. if that will help understanding the problem

Edaboard provides each member with a space to store attachments (files, images, etc.).
Click 'Go Advanced'. Click Manage Attachments. Upload your project as a zip file (compressed).

You can see further directions by clicking the Help tab at the top of this page.

thanks below is my design i am using l network to match the antenna geometry(battery+connector+feed1)

and the design how i found the input impedance

see my design

since my antenna impedance is really small i am worried whether it wrong also if this is correct will it be possible to match this to a 50 ohm impedance. someone told me that will not be possible since the change required in the real part of impedance is in order of 1000( 0.05 to 50 ohms).

hii i am making an antenna whose input impedance is really small (0.05+j33.36) so if i use a lumped matching network to match this to 50 ohm then feed this structure with a 50 ohm line then it should be matched but my input impedance is still same as it was before using the matching network. why is that happening?

i am simulating this structure in hfss and have used the rlc boundary for the lumped elements.
is this due to matching network is not working or it is not possible to match this small impedance to 50. as the variation in the real part is of the order of 1000(0.05 to 50).

can someone tell the possible reasons why this is not working



or what is the minimum antenna impedance for which is matching is possible by using lumped matching networks