thickness of ground plane of microstrip antenna

[vishal_sonam]

Hello
i have designed and simulated a high gain microstrip antenna by using ie3d and now i have to fabricate it. so i want to ask that what should be the thickness of the ground plane and the thickness of patch in ie3d.
thanks

 

[ferdows]

if u design microstrip u should know that both side of substrate has a same thickness metal

 

[volker_muehlhaus]

Due to skin effect, RF current flows only on the surface of the conductor and there is no need to use very thick metalization.

Calculate the skin depth for your frequency of interest.
Calculator for skin effect depth

Example: Copper at 1GHz results in a skin depth of 2µm. This means that a "standard" copper thickness (e.g. 17µm) is perfectly fine. Using thicker copper will not reduce losses.

 

[vishal_sonam]

Hello ferdows, actually i am new to antenna world and i have spent only 6 months on this and designed 1 antenna using ie3d and now i have to fabricate it so i dont have enough experience.
i have used FR4 for my designed and i dont what should be the thickness of ground plane.

 

[enjunear]

Due to skin effect, RF current flows only on the surface of the conductor and there is no need to use very thick metalization.

Calculate the skin depth for your frequency of interest.
Calculator for skin effect depth

Example: Copper at 1GHz results in a skin depth of 2µm. This means that a "standard" copper thickness (e.g. 17µm) is perfectly fine. Using thicker copper will not reduce losses.

1 δs (1 skin depth) is equal to the depth at which current density has fallen to 37% of it's surface value. In the RF design world, use 5+ skin depths at your lowest frequency of interest. This ensures the majority of the electrons have "room to move" (see topic: current compaction).

**broken link removed**
Skin Effect - Daycounter, Inc.

 

[ferdows]

both side of FR4 has metal so u dont need to do any thing


i hope it useful for u

 

[frodonet]

Hello
i have designed and simulated a high gain microstrip antenna by using ie3d and now i have to fabricate it. so i want to ask that what should be the thickness of the ground plane and the thickness of patch in ie3d.
thanks

Ground thickness plane in the design is ideally 0 and the metal patch is 0.

If you fabricated an antenna before, it works like this.

The substrate is actually embedded with full metal layering ontop and bottom. Meaning that the substrate at the middle covered with metal at both sides.

Depends on type of fabrication, now they are using different methods, the metal will be cut away slowly until it follows your antenna design. Basically, the substrate is untouched. Of course the metal have a certain thickness, but you can't control it, it's assume to be as low as possible. The metal already been fabricated with the substrate...you can't do anything about that.

 

[enjunear]

1/4 oz copper should be sufficient down to 1.5 GHz (1 skin depth = 66.17 microinches, 5 skin depths = 0.331 mils.... 1/4 oz copper = 1.4 mils/oz * 0.25 = 0.350 mils thick). Higher frequencies will have less skin depth, so you can always go up in frequency and not suffer from current compaction.

 

[volker_muehlhaus]

The metal already been fabricated with the substrate...you can't do anything about that.

The substrate manufacturer does give you a choice between different metalization types.

For substrates like FR4, you can choose from different metal thickness, because the low frequency/power guys sometimes want thick metal for lower ohmic loss at DC. For 900MHz, see skin effect discussion above.

For "RF" substrates like Rogers, you can choose different thickness and also between different roughness values (smooth rolled copper is the electrical engineer's choice for lower loss, rough electrodeposited surface has better adhesion to the substrate over temperature cycles).

https://www.rogerscorp.com/documents/749/acm/Copper-Foils-for-High-Frequency-Circuit-Materials.aspx

 

[frodonet]

The substrate manufacturer does give you a choice between different metalization types.

For substrates like FR4, you can choose from different metal thickness, because the low frequency/power guys sometimes want thick metal for lower ohmic loss at DC. For 900MHz, see skin effect discussion above.

For "RF" substrates like Rogers, you can choose different thickness and also between different roughness values (smooth rolled copper is the electrical engineer's choice for lower loss, rough electrodeposited surface has better adhesion to the substrate over temperature cycles).

https://www.rogerscorp.com/documents/749/acm/Copper-Foils-for-High-Frequency-Circuit-Materials.aspx

Thanks for sharing. I didn't know about the customization of the metal thickness.

 

[vishal_sonam]

i still have 1 query,
my design has stacked patch so one patch is in air so what will be its thickness.

 

[enjunear]

Thanks for sharing. I didn't know about the customization of the metal thickness.

With rolled copper, you are generally limited to a range like 1/8 oz, 1/4 oz, 1/2 oz, 1 oz, and 2 oz copper (copper weight per sq. foot), which can vary by manufacturer. With sputtered, it's more flexible, but I've never used it in practice (only done sputtered metal on Alumina substrates for high freq circuits; on the order of 100 micro-inches, and used gold).

---------- Post added at 21:43 ---------- Previous post was at 21:35 ----------

i still have 1 query,
my design has stacked patch so one patch is in air so what will be its thickness.

If this is just for simulation, then pick a thickness that will give you at least 5 skin depths (see previous comments as to why). If you are planning to fabricate this, then you'll need to have some kind of dielectric to go between the top patch and the substrate. What do you intend on using for this "nearly air" spacer? (some plastics get down to Er around 2, but that's still going to disturb your antenna design, since it's not Er = 1).