HFSS and CST are 3 D EM simulators based upon different computational techniques. HFSS is based on Finite Element Method (FEM) which is more accurate for designing antennas while CST is based upon Finite Integration in Technique (FIT) and is also popular among antenna designers due to ease in simulations. However results of both the simulators are not same becaue of different computational techniques involved. HFSS results are close to experimental results with more insight into the structure available. ADS is used for circuit co simulations where active components are also involved. It can be used for planar antennas as well and is based upon MoM (Method of Moment). AWR, i used while simulating different kind of filters but dont know the details of this software.

HFSS and CST are 3 D EM simulators based upon different computational techniques. HFSS is based on Finite Element Method (FEM) which is more accurate for designing antennas while CST is based upon Finite Integration in Technique (FIT) and is also popular among antenna designers due to ease in simulations. However results of both the simulators are not same becaue of different computational techniques involved. HFSS results are close to experimental results with more insight into the structure available. ADS is used for circuit co simulations where active components are also involved. It can be used for planar antennas as well and is based upon MoM (Method of Moment). AWR, i used while simulating different kind of filters but dont know the details of this software.

All mentioned software gives near practical values at their respective area. it depends how much near is your design with practical realization.  CST = passive and Active circuit simulation. HFSS = Passive circuit Simulation. AWR = simple 2D simulator, ADS = Active/passive lumped model simulator.

I do agree with Pragati Patel.

@pragati patel, Do you have experience with all softwares, or initially did u used them

I have used HFSS and ADS 2011. HFSS is for electromagnetic simulations. Its basic solver use FEM (Finite Element Method). It has ability to obtain fast solution. That is very important if you are to tune your design. Also then new versions 13 and after has integrate MoM (Method of Moment) solver with wich you can for antenna design. The MoM does not require any boundary conditions so you simulation will run faster. Also it gives more accurate results for antenna design.

The ADS use mathematic models to simulate behaviour of active and passive elements. It has commercial passive and active components. It is very useful if you have to design any microwave system.

ADS can do electromagnetic simulations. It use MoM and FEM solvers. Its MoM solver gives very accurate results when you simulate planar structures.

 @ Salman Arain, Currently i am using CST Microwave Studio for designing dielectric resonator antennas. But during my masters i had used HFSS, ADS and AWR. 

@Pragati Patel, That is very good, If you have any good learning material regarding these software can you kindly share it with me

My email is [email protected]

I also need hfss related material at [email protected]

On top of all comments from the others, there are some addition facts you need to know, as an experienced user.

The Time domain of HFSS is not as good as CST. If you want to work with radar, time response, CST is much better. CST also has a built in Design Studio for simple circuitry co-simulation and new signal type feeding but HFSS cannot do all of these.

HFSS FEM is much better than CST-Frequency Domain. HFSS meshing engine also much better than CST in term of mesh connection and validation. In CST, meshing sometimes has a lot of "suspicious element" but in HFSS, you will not see this coming. The curvature mesh in HFSS also better by appearance.

HFSS IE solver is a cheating solver where u can create a very small box for your passive design including entire jet. It is really lightning fast solver for the same structure as compared to CST but it requires gigantic RAM.

because my old place has all of these simulators, I always run HFSS-IE for my initial design, then use normal HFSS-FEM for finer simulation, then export to CST to run a Time Domain for comparison, then use ADS to do circuit simulation.

However, just recently I realized that the ADS 2014 has no built in Avago Library... The installed rfLib is empty. Those non-linear device such as Avago's commercial Diodes was included by default in the ADS2009. I am now having problem to get the old library back.

I advise you to have a look up to this file consisting in on a survey about EM simulators either  differential as FEM used by HFSS and FIT used by CST or integral simulators like  FEKO , momentum ADS using MoM.

Also HFSS is used in frequency analysis unlike CST which is performed in Time analysis....

i am getting different results of same circuit values using ADS and AWR software. Can somebody tell me the difference

Hi every1. can some1 advise me on which of the tool is suitable for my work? i am working on Branch line coupler.

hi for branch line couples ,you can use ADS  

Between ADS and HFSS which one is most suitable for design of mmWave RF SoC and a plastic waveguide as a channel.

@Wai Siang Yeoh, the old library is still available in ADS 2016. You need to extract them from zip file named "HFDiode_vendor_kit.7z" under "\ads_folder\oalibs\componentLib". You should be able to include them then.

Many different types of electromagnetic simulators have been introduced yet.  Your list contains only some of the well-known simulators. Based on your mentioned softwares, I can give you some advice.

You can define and simulate very complicated structure using HFSS or CST. They can be employed to simulate very large structures depending on your available hardware resources.  I can not tell you for sure that HFSS is better than CST or vice versa. For some structures, HFSS is faster and lead to better results while CST may be better for some other structures. 

If I want to compare  AWR with ADS, I can tell you that both can be used to simulate 2.5 D structures. AWR has EM environment that you can define your structure while ADS offers you Momentum that can be used to define and simulate different types of 2.5D structures. Definitely, Momentum is more powerful than AWR EM environment. Both tools have also circuit simulation environments with different libraries that contain various models of active and passive components. You can define many different types of active or passive circuits and simulate them.

Depends on the structure and better to use accordingly.

Thanks for your responses. I appreciate

Why don't you read what the vendors of those software tools say about the latter, instead of asking us to feed you with a spoon?

HFSS and CST are electromagnetic simulators... You can explore antennas in these softwares..... AWR is circuit simulators...you can design RF Circuits..In ADS you can design RF Circuits at low frequency and at high frequencies. You can also study about antenna structures, couplers, and other distributed models....