tomasbj

I thought this worked on: Downlink (Satellite to User Terminal): 10.7 GHz to 12.7 GHz Uplink (User Terminal to Satellite): 14.0 GHz to 14.5 GHz Considering that nowadays satellite constellations is a demanded topic, I think now this post is really useful. My questions below: 1) What are these cross patch shapes for? Directivity control, so that more gain? ... Surely the cross shape is for circular polarization achievement/improvement. 2) So... they use slot feeding mechanism?

Awesome collection. Good job.

HI mate. Do you have this model in CST? It is awesome! I would like to try to make it with Circular Pol. Thanks

Two ports are well isolated because two orthogonal modes are being exited with this configuration. Bandwidth at S11 -10dB is reduced.

Very simple and intersting performance. I guess Circular Pol will work well too by using two of these orthogonal oriented and 90º phase shift. I wonder how to make this much smaller. for the same frequency band.

@Ukamurubasu, active S-parameters or F-parameters in CST are useful for phased arrays, or antenna systems in which one would like to quantify the coupling effect between both antennas. This is useful if and only if you use simulataneous excitation. Otherwise there is no sense to look at this active S-parameters. These are measured when the device under test (DUT), such as an antenna, is in an active state, i.e., it is powered and possibly transmitting. In this state, the antenna or network can exhibit different characteristics due to the influence of active elements like amplifiers or transistors. Active S-parameters are crucial for understanding the performance of the device under real-world operating conditions. They can provide insights into parameters like active input and output impedance, gain under active conditions, and the stability of the device when transmitting. This is very important in phased arrays, beamforming. The conventional S-parameters we use to work are called passive S-parameters. You get it! Added to this, calculate the reactive near field at the corresponding working frequency and check their separation distance on your satellite. So that if they are inside of the near field sphere, avoid it!. Because mutual coupling will be there.

Very interesting. Thanks for sharing. Learning a lot in this forum.

I agree. Really interesting, BTW

How is the central part? are X-oriented and Y-oriented antennas touching each other?

Hello, could you please help me with finding the matching between the design I made and the paper. I can not find the same results. See attached file. cst2021 Thank you spiral_v5.cst

I see this antenna is connected to the reflector to the other side of the feeding. Why? and what is the difference between connecting it to ground or not at that end position. Thanks

Could you please explain how the wire ends in this design? Apart, I understand the wire lenght should be lambda/2. Am I right? Do you have a .cst file to check the design? Thanks in advance for your help.

Very interesting, Thanks for sharing! I was working with Rohacell Since it has very low relative permittivity and low tangent loss too.

Very interesting model! Any generic rule for the design? thanks. I mean explanations.

Very interesting Could you please share realized gain vs frequency? S11 too? I see you are exciting two orthogonal modes and breaking simetry with truncated corners and U-slot. What is the benefit of this? increase the bandwidth? Improve the axial ratio?

Hi Guys, Why not one on top each other as gnss antennas. I mean, to make more compact this idea?

Hi Guys, What is the loss tangent of this material?

Sure. I understand that this circuit solves the gain problem. I have never used somehitng like this. Thanks for your suggestion

Hi guys, I was impressed when searching online and I saw the 315MHz Rubber Duck Antenna. How is that possible? What is the shape inside of it? How can an antenna of 5 cm length to have a gain of 2 dBi? Please check this link: https://ctrfantennasinc.com/small-315-mhz-antenna-low-profile-antenna/

Hello, thanks for your answer @Admin . Apart, to make this antenna work at those frequencies and have 2dBi gain... should this antenna have an amplifier and matching network? I made my own model and the gain is very low. Thanks in advance for your help.

Invalid SAB file, import failed! Thanks anyway.

Hello, I am interested in the replication of this antenna. Could you please provide me an cst file of it? I see the feeding mechanism a bit difficult to make. Please check file attacged. Thank you in advance. ESA_example.pdf

Hello, could you please share the file as IGES or STEP format, I will then import the neutral file into my 2021 version. 2023 is impossible for me to install it. Thanks in advance

Hi Dr.Pepper, have you developed the data base? Let me know and I will contribute. Although we can share in this forum too. In a near future I will. I like it. The help in this forum is really good and deserves it.

No, you are right haha I am interested on these type of antennas. In fact, I want to use this antenna solution to cover 30-170 MHz, with gain higher than -25 dBi. And consider a weight to be less than 1 Kg. A very challenging antenna. But who knows... perhaps, including ferrite and some dielectric materials I can achieve it. Otherwise... I will try another technology. Thanks for your support and asking.