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68 Threads found on biff44
reflection coefficient and VSWR are measured in exactly the same way. not sure what you are talking about. I disagree with biff44,VSWR and Reflection coeff are not measured in the same way. To measure VSWR Vmax and Vmin of a standing wave is measured,using a probe,this is an ancient method when directional couplers
yeah that is fairly normal. But with the resonator attached, it should NEVER oscillate at those other frequencies. Not every time.. If an oscillation conditions appear with some parasitic elements, the resonator may not maintain this condition ( Closed Loop Gain and all over Phase Shift) anymore at certain frequency.
Anyone know an experienced millimeter wave contract manufacturer in North America that can do 30 GHz work? 71 GHz work? I am making a list but it has not too many names on it so far. I have worked as a chief scientist with Spacek Labs. Inc in Santa Barbara, CA. We have developed many challenging prototypes from
is not an alternative. The CA3083 is 5 independent NPN transistors. (I did not specify it at post #1) Searching, I have found the TCA671 which has 200mA Ic. I will connect all the emitters together, so it is ok that two trans
Dear biff44 I want to to design an antenna at any frequency but the problem here; how can i model the CNTs on CST or HFSS. In the case of copper patch, we choose a specific parameters and the model of Copper is included in CST library. Therefore, i want to model the CNTs instead of copper.
dear biff44 our concern is while tilting the ground plane to 45 degree any distortion will happen to the radiation pattern(azimuth & elevation)
yes, sorry, I'm using it as a downconverter, with DC coupled I and Q outputs Does it work for you ??
I'm agree with biff44. There is another resonance coming from a different source rather than antenna. A patch antenna can not present such a very sharp S11.There should be another source like an open circuit or short or something else..
97351 yea tried grounding them, bt the problem become exactly the reverse i dont get any sort of output irrespective to switches - - - Updated - - - biff44 sorry dude cudnt get you, i just tried it on a breadboard & not on a protoboard
circulators do not have 2nd harmonic suppression built into them. add a lpf if u need that. You might luck out with higher loss at the 2nd harmonic, but no guarantees Thank you for your reply. Now I faced a problem is that, when Pout=200W cw, before circulator, the 2nd harmonic is -50dbc, but after the circulator
It is a true shame that some small company has not come up with affordable spectrum analyzers and network analyzers by now. There should be a two port DC-10 Ghz vector network analyzer out there for maybe $4000 USD. There is not much inside of these things--it could be done on one PC board. I have a project, for instance,
transistor--emitter to ground, collector to series resistor R1. Load to 5V. Other side to resistor R2 to ground, and in parallel to that resistor is transistor/resistor combination above. Transistor open: load is current limited by R2. Transistor closed: load is current limited by R1 || R2 In the circuit shown i
biff44 a way I used many times is the following one. Once you get calibrated to the input pins of your differential device, apply the equation: and get the result. There is a paper explaining the math behind this, I'm not able to find it now. Easy, but not a direct measurement. I hope it c
@biff44: The equations that I linked to, and the equations used in the online calculator in post #7, are designed for multi-turn inductors. I am working on inductor analysis with EM simulators, but use these equations as a starting point. click! From my experience, the equations
Recently designed a patch antenna in Sonnet on FR4 board. The design went well, and the measured S11 is very similar to the redicted S11. But the measured gain shows the FR4 material is low Q, and lossy enough to effect the gain significantly. Sure? If the substrate losses are higher than simulated, the S11 curv
thanks guys a lot... At first I was going to say it could not be done with a simple dipole receiver. But on thinking, if you AM modulate the RF signal, and then transmit it with the cp should be able to rotate the dipole antenna while detecting the envelope and watching it on an oscilloscope. You should be able
Just off the top of my head, I would say: Marki Microwave??? Yes, Marki is a company which makes microwave component.
....right up to the point where the layout guy said it died while inputing it to Altium. Do you have a more exact error message? The Sonnet rectangles are polygons are exported as DXF POLYLINE objects. These POLYLINE are closed and have zero width. If there is a cutout in a polygon, the POLYLINE might be self-inte
Anybody have any signal processing programs, or know places to download these, for a SP601 EVAL board. I have a hittite HMCAD-1520 digitizer that is on a mezzanine board, and plugs right into the SP601. I would like to do some simple FFT processing...amplitude and gain of signals, demodulation, etc. Thanks, Rich
Hi biff44, AD9434-500 from Analog Devices samples at 500 MHz with 12 bits. Near, but not enough. Why about using two ADC's with sufficient analog bandwidth, converting at half the composite sampling rate? With the same input, they sample at interleaced times. If sampling simultaneously, one of the inputs should be delayed 1.7 ns. Regards Z