Andrew77

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...

these are the best (to my opinion) AN for Helical antennas HIGH GAIN AXIAL-MODE HELICAL ANTENNA WITH metallic disk.pdf Low_Pitch angle Helix Antenna.pdf Optimization of Helical Antennas.pdf

MMMM 35 dBi gain maybe with an amplifier Looks like a wideband monopole

I've designed a helix for 432 MHz based on the studies of the paper attached, This is a WB1 design centered around 432 MHz, length is about 0,8 wavelength and a metallic disk is placed in front of the antenna in order to increase gain Simulation is performed with cst Integral Equation Solver, surface meshing is visualized on the picture Optimization of Helical Antennas.pdf Helix_433_5_with_disk.cst

Can I put more than one disk?

Other Simulations with disk gives me poor axial ratio I didn't test just this