# Search results

1. ### question on LNA stability

Hi Guys, I am designing an LNA at 2.4 GHz. I am a beginner. The transistor is NEC3210S1. When I use an ideal capacitor c7=200pF, the stability is OK(the second picture). But when I changed to a real capacitor model ATC700B201JP300 200pF, the stability became worse(the third picture). I tried...
2. ### cannot get .hb file from HSPICERF

Hi Everyone, I try to run an example from hspice@RF user guide. It is example 2, Power Amplifier. .options POST accurate .param f0=950e6 PI=3.1415926 Ld=2e-9 Rload=5 Vin=3.0 .param Lin=0.1n Vdd=2 Cd='1.0/(4*PI*PI*f0*f0*Ld)' M1 drain gt 0 0 CMOSN L=0.35u W=50u AS=100p AD=100p +PS=104u PD=104u...

HFSS and designer Hi, I have two microwave components to simulate. But it is difficult to simulate with HFSS. So I want to extract the data to designer and simulate. I don't know whether it is data link or dynamic link. Does anyone have some example that I can follow? Thanks!
4. ### T-junction power divider

Hi everyone, I want to design a T junction power divider from 12GHz to 24GHz. But there is always a resonance peak at about 21GHz. Then I change the length of the arms, the peak can move a little bit according to it. Does anyone can help me to figure it out? I set up one port as 25ohm, and the...
5. ### FDFD method to solve eigen value problem

fdfd method Hi Everyone, I am using FDFD method to solve eigen value problem, like a microstrip line. The software I am using is Matlab. But when I refine the mesh, say 200 by 120, the final matrix would be 143041 by 143041. The matlab cannot handle that. Anyone have a good idea to solve...
6. ### How can Labview help developing MCU

Hi, can anyone do me a favor to describe how labview can help develpoing MCU. I am new to MCU, and I heard labview can make it easy. Better describe in detail in hardware and software. Thanks !
7. ### questions about moment of method

Hi guys, I need help regarding moment of method. At the last step, I already got the mattrix for a homogenous equation group. And by setting the determinant to be zero, I can get the unkowns, such as the phase constant. My questions is, for a high order equation ( The number of the basis...
8. ### full wave analysis with Fourier series

Hi everybody, I meet a big trouble when I want to analyse the microstrip with full wave analysis. Attached is a paper about that method. I don't want to use the new method metioned in that paper. I just want to use the traditional method, which is the first part of that paper. I appreciate...
9. ### energy of the even mode and odd mode in coupled MSL

site:www.edaboard.com even odd mode Hi everyone, I am studying coupled microstrip lines right now. And I am confused by a questions. Do the energy of even mode and odd mode equal to each other when the V1=1v, V2=1v (voltage on each strip)for even mode and V1=1v, V2=-1v for the odd mode...
10. ### analytical expression of electric field in microstrip line

Hi everybody, Is it possible to get an exact analytical expression of the eletric field and magnetic field in a microstrip line? Thanks! pudding
11. ### HFSS simulation result fidelity

Hi all friends, I have simulated an antenna with hfss, but I find the results are different when I set different solution frequencies from 2.5GHz to 3GHz. I don't know why. Which results I can believe. I have uploaded the files and results. Any suggestions or advise will be appreciated...
12. ### Antenna directivity problem in HFSS simulation of a circular patch loaded antenna

Hi Friends, Recently I use hfss to simulate a circular patch loaded with annualr ring antenna. S parameter is ok, but the directivity is below than 1. I seed the air with lambda/10, and the boundary is lambda/4 away from the radiation element, but the result is same. Anyone can give some...
13. ### strange antenna parameter

Hi friends, I recently use HFSS to simulate a annualr ring loaded circular patch antenna, but I found the parameter is somewhat strange. Because the maximum directivity is less than 1. I think it doesnot make sense. The maximum directivity should be larger than 1. Can anybody tell me what's...
14. ### strange antenna parameter

Hi friends, I recently use HFSS to simulate a annualr ring loaded circular patch antenna, but I found the parameter is somewhat strange. Because the maximum directivity is less than 1. I think it doesnot make sense. The maximum directivity should be larger than 1. Can anybody tell me what's...
15. ### simple questions about the microstrip line

Hi all, Can anyone tell me how to get the conductor and dielectric loss from S21 and S11? Thanks a lot! pudding
16. ### calculation of characteristic impedance

Hi all, I want to calculate the characteristic impedance of a microstrip line on a two layer substrate. Because I cannot let this substrate to touch the port, so I cannot get the Z0 directly. Can anyone tell me how can I get the Z0 of this kind of microstrip line? Thanks! pudding
17. ### feed dipole antenna on surface

Hi all, I met a question when I want to test a dipole antenna. I print the dipole on glass, but I don't want to drill a hole through it. So I want to feed the dipole on top of the glass. Can anyone give some advice on it? For example, what structure I should use to feed it. How to connect...
18. ### Question about the connection of the stripline with the connector

Hi all, I have a question about the connection of the stripline with the connector. The conductor of the stripline should between two dielectric, but that way how can we connect the conductor of the stripline with the launch pin of the connector? By the way, is there special connector for...
19. ### patch antenna with probe feeding

Hi all, I am designing a patch antenna with probe feed from the bottom of the patch. Because it is my first time to do it, I have some questions: 1. I am not quite sure what kind of connector and lauch pin I should use. 2. I also want to know if I need mount the patch antenna on a larger metal...
20. ### How to use macros in HFSS 10?

Hello, I have a simple question for macro. If I want to use macro in HFSS10, need I install other software or use it directly in HFSS? If I don't need to install other software, how can i lauch macro editor in HFSS10? Thanks