Search results for query: *

Well, the only advantages of FR-4 is that it is cheap and it is good enpugh for RF circuits. Disadvantages are changing RF properties depending on vendor. Problem is that every vendor prepare the whole material itself. Compared with for example ROGERS materials, which are very stable despite...

It is OK to manufacutre such a width. The only think you have to consider before you will order your PCB is what type of software did you use for optimization. If it wasn't any real 3D or at least 2.5D simulator so You have to expect that measured results compared with simulations will be more...

ADS or Microwave Office should handle this.

Well, You're right. There is nothing like B=uH+J. I was wrong. As I said it was long time ago. Current density is present in maxwell eqn.: rotH=dD/dt + J which says that variable electric field will cause magnetic field. B=uH is material eqn. and it can be written as: B=uH + M where M i...

Hi! B=uH is just a simplified Maxwell eqn. In real, it should be written as B=J+uH (isn't it??? ). J is ommited in some discussions because it's not present or its influence is so small that it can be ommited to make calculation easier. If we additionally assume that B, H and J are all vectors...

The efficiency of your antenna will be very dependant on dielectric material. As You probably know most of dielectric materials are much more lossy then air. Also they are trying to keep electric field inside. So, if You want minimize the size of antenna with dielectric load, be carefull. You...

Hi! Using 0Ohm as "thru" and "short" and 50Ohm as "load" will not help You with solving this problem. If You would like to do like this You would have to modify standard definitions in Your network analyzer. There is posibility to introduced "user kit&quot...

Hi! Try one more time. In the meny on the left side go to "our products" and then open "broshures". You can open the first one ( mws4.zip) : CST Microwave Studio. Ther You will find just a short note about the model in the middle of document. But trust me, I was on...

Hi! It strongly depends on the design. Sometimes, when the board is very big, ground plane on top side is used to make the whole board more rigid. In this case groung vias are necessary and placing them is also very important. Buding.

Hi! I would like to add one more point of view. Antenna used i such a device is always pointed, in some way, towards the ground. And, as everybody knows, it gathers the thermal noise from the ground. During the night situation is much better. To avoid such a problems You have to make good...

Hi! I'm not sure if this is what You want, but I saw such a model of human body for high frequencies simulations in CST microwave studio. It allows to analyze the impact of em waves on human body. Check : www.cst.de. Good luck. Buding.

Hi! The most of cables nowdays are 50ohm or 75ohm. Just check the matching. Buding.

Hi! I had opportunity to work with SONNET few times. Very easy to learn, and userfriendly. Good procedures to make analysis faster and easier. Good accuracy. Possibility to place many metal layers ( i.e. MOMENTUM has only two metal layers ) Possibility to improve thick metal layers. many more...

splits the signal, and output signals are shifted in phase with 90 degrees. Buding

What kind of feed system do You use? Maybe it is possible to improve bandwidth by making better feed circuit.

Hi! I used SONNET software for microstrip antennas. Results were very good. I designed 2x2 patch array for 12 GHz feeded by coupling thru aperture. Whole design was very complicated and I was very suprised when my measurements were almost the same with simulation. I reccomend this software...

To Ikuzu: When You use EM simulations You will always have freq. shift. For example in ADS differences between model simulation and momentum, on freq. like 14 GHz are usually 1 - 2 GHz. I always trust momentum. Model analysis I use only to estimate start parameters. To max232: To compare two...

Is it such a problem?? Try to simulate in ADS normal microstrip notches plased side by sides, tuned to proper frequencies and You will get BPF, LPF,HPF, whatever You want. Every thing will depend on quantity, spacing and matching of notches. Good luck, Buding.

As I know it is enough if You know VSWR. Bandwidth of the antenna will be the bandwith were VSWR is < 2. Buding

Hi! Just check with different producers (ROGERS, ARLON, MATSUSHITA etc). They have core materials with thickness even 0.1 mm. They use also prepreg materials with thickness about 0.05 mm. Contact them. Good luck. Buding.