Dimensions of MicroStrip Patch Antenna

HI,

I am newbie to HFSS and antenna simulation.

I have gone through some online tutorials but I have few queries.

1. How to select the substrate thickness and di-electric constant?
2. How to determine the dimensions (L, W, Thickness) of patch to be used on di-electric?
3. I used HFF now but I didn't get upon what calculations we need to give co-ordinates for Patch/Gnd plane/Feed when we create box?

Please let me know how to proceed.

Thanks!

Hello Shaikss

If you are into the field of antenna's, First thing that dictates the requirement is your substrate and dielectric constant. For instance you want to fabricate an antenna for a specific purpose,you will have the physical and electrical constraints that go in for choosing the substrate. so what is your antenna being used for in which condition? that answers your first question.

How to determine the dimensions, there are equations governing the values of L,W and so on.Refer a book an antenna theory,my suggestions Balanis or pozar.

How do you draw and co ordinate your patch,ground plane and feed. first feed using the equations determine where is your 50 ohm point or the point of resonance . thats your feed point and then patch dimensions are calculated from the step 2 from the book. ground plane, make sure the ground plane is large enough compared to the patch and check the infinite ground plane when you set up the boundary condition for the patch,if required.

There are so many of these tutorials which tear down the complications to such a basic level.

Hope that helps.
Rotmanlens.

Go through this link: em: talk - HFSS Tutorial 1: Microstrip Patch Antenna

-sv

Thanks for briefing it down Rotamnlens.
I will let you know my requirement.
I am now into design of RFID antennas at 865~867MHz UHF band. I want to design small sized antenna but possessing long read range so that the entire tag(chip+antenna) fits onto wrist band..
I want to design 2 antennas. Txing side....Yagi antenna and Rxing side dipole antenna.
Depending on the above requirement, how should I select the substrate di-electric, thickness?

Suppose, if I want to draw a cylinder in HFSS, I need to give radius, height, length etc as inputs. How should I select these values?
Please clarify me.

Thanks in advance.

I searched about patch antenna and I find some calculator about them
so please see this page
em: talk - Microstrip Patch Antenna Calculator
for the thickness and dielectric constant you can see the datasheet of different company's products.for example roggers
for some cheaper substrate for example FR4 for thickness 1.2 mm you can use permittivity=4.4 and tand=0.02