coax feeding for slot excited two layer dielectric hemispherical resonator antenna

[nexttym]

hi..
i need to simulate a two layer hem. dra,slot excited..and the slot itself is fed with coaxial cable..the slot is in ground plane..i am new to hfss..
donno which type of excitation i should give to the port..and i'm also confused about the thickness of ground plane and the thikness of slot..

---------- Post added at 14:34 ---------- Previous post was at 13:51 ----------

need to do the simulation with hfss

 

[ferdows]

hi
DRA usually fabricated on microstrip so u can define the ground plane with no thickness
and for port you can use both of lump and wave port but if your antenna is UWB better u apply wave port
for more information u read the work of ahmed kishk in university of Mississippi at IEEE

 

[nexttym]

thanks for the reply...but i have to simulate a wide band two layer hemispherical dra,excited with an annular ring and the ring is excited with a coaxial probe..
thickness of the slot is another issue..
wil always be thankful for the help

 

[ferdows]

hi
i read the paper but the figures which show the antenna are not clearly and and it is ambiguous

 

[nexttym]

@ferdows: yeah..exactly..its really ambiguous..had been tryin for two months..pls intimate if u get any clue..
thanks alot for the reply..

 

[ferdows]

i will read paper fully but i think it a metal plane with a ring slot and coaxial placed under it and the core of coax take out from coax and this length equal differential of outer and inner radius of ring
and on the top of slot they put the DRA and for ground u dont need to thickness

 

[nexttym]

hi..
i tried out with 0 thickness of ground plane..but for slot,i guess there should be some thickness...right??i did with 0.003mm thick slot(vacuum) and put pe boundary at the bottom faces..stil the results are not matching with the paper..can v give the slot with 0 thickness??whenever i do like that i feel somethin is missin..sheet properties comin to be 'UNASSIGNED'...donno what proprty to assign..

 

[nexttym]

hi...
pls see what all are the problems with my design...i am uploading the simulation program..pls be kind to see to it..
I did it in 2 ways..please see both and tel me which is better..

 

[ferdows]

hi dear
u must put your coaixial under the ground but it in ground and u can give a little thickness to your ground , and it make u able to join it to outer layer of coax
try again

 

[nexttym]

then slot also should be given some thickness,rite??wot type of excitatio do u suggest in such a case??

 

[ferdows]

i think for this antenna we can use both but i prefer lump port

 

[nexttym]

@ ferdows..thanks alot for the concern..i did the simulation in the way u told..here i'm uploading the program please go through..please verify the boundary conditions and excitation..i've given
1.pec for the ground plane(thickness 5mm)(pec assignment for the whole structure)
2.pmc for the annular ring(thickness 1.5mm)
3.wave port(if i'm givin lumped port error is comin)
please find time to help me..thanks alot..

 

[ferdows]

hi
your simulation has some small problem and i change them but the result not ok
and in the paper they did not announce the coax ????

 

[nexttym]

can u mention which al were d problems??n in the paper,its given in ref to figure,rite..