Andrew77

Hi, further improvements for the matching: check this

Have you tried to get the GND closer to the antenna? VSWR gets better! In this case GND plate moved to the antenna by 6 mm

Yes, It Works! Have a nice day!

Hi Dear, Please could you send me the *.stp file? Because I'm using CST2019, Many thanks! Andrea

Gain VS frequency? Thanks!

Hello, I'm trying to design a NFC antenna @13.56 MHz for a reader, Antenna should have around 1,24 uH of inductance as simulation and calculation verified, but i'm not very sure about the set-up of CST (Frequency domain solver) I don't see Self-inductance up to 60 MHz I don't find The example given in the Examples of CST: "RFID Reader-Coil, 13.56 MHz CST example" could someone upload? (CST 2019) Many thanks NFC_13_56_MHz_V2.cst

I already posed a question about this antenna, I made some simulations, have you succeded to simulate it?

mmm interesting, but seems lumped port, I don't understand well... Do you have this example in .cst format?

Sure, The antenna is not matched.. Here is just to check the settings... CST_Article138_RFID Reader-Coil, 13.56 MHz.pdf

I past it again... Simulation are same as mine Did you use Transient solver? if not what mesh? Your bounding box how big is? NFC_13_56_MHz.cst

here is the original antenna: NFC_13_56_MHz.cst

Hi dear,how are you? I made antenna by myself, I understand that corners must be rounded but I started with this version to have a simpler meshing... The version with rounded corners gives me quite the same inductance (around 1.24 uH) I'm looking for the examples inside CST (13.56 mhz coil ) but I have a big db file for examples in CST directory so I don't kown how access Andrea

OOK thanks!

could you post the .cst file for this antenna? thanks

Seems that VSWR and gain go to the opposite direction!

,,,under simulation the real antenna... Dual_Band_Flower_Pot_2.cst

Ah! OK, I thought the spiral worked as a choke only... I will try

yes must be so, the coaxial cable is inside a pvc 25mm conduit tube, anyway its effects are very low

dual-band-half-wave-flower-pot The simpler version, Looks like to have the higher gain @410 MHz VS 430 MHz Dual_Band_Flower_Pot.cst

Yes, I fix it; 5,5M Meshcells, lot of time to simulate...

under simulation... Need time.... Dual_BandHigh_Gain_Flower_Pot.cst

ook thanks, will CST simulate well a coaxial cable with transient analysis ?

Hi! this is the antenna, http://vk2zoi.com/articles/dual-band-high-gain-flower-pot/ RG58, sleeve is a copper/aluminium or brass tube How you would simulate the 7 turns of coaxial cable? thanks

How would you simulate this antenna? This is a collinear 144 + 430

In reality, before doing that, I would like to know if this antenna has a 3dB HPBW around 100° or maybe something wider beamwidth than a traditional helix...