Recent content by uWave_Matt

  1. U

    Malleability and bending of metal at cryo temp

    Perhaps the shrinkage is significant enough to cause loss of contact and I was trying to over-complicate it. It'll go down in the lab notebook and thesis as "possible explanation." Thanks to both of you for expelling this unbending business from my mind.
  2. U

    Malleability and bending of metal at cryo temp

    I think the broadest way to frame this question would be as follows: "If a metal conductor (copper wire) were bent at room temperature, then placed in a cryo-cooler and cooled to ~30-80 kelvin, would it experience any 'unbending?'" More specific to the situation, I've bent down the center...
  3. U

    Input Impedance MESFET

    Actually, if you want to use just one tuned section and widen your BW, the only thing I can think of is over-damping it to lower the Q factor. You'll choose resonance to be maybe around 8GHz, then vary your resistor to increase or decrease BW. Higher resistance is higher damping, lower Q, and...
  4. U

    Input Impedance MESFET

    Graphically, your reflection coefficients on the smith chart should give S11 which should be your normalized input impedance. Just multiply by 50 (or whatever your characteristic impedance is) to get actual input impedance.
  5. U

    FET simulation software

    I'll pick up that book and see what I can figure out. I'm actually fabricating (or attempting to fabricate) the transistors myself. I have an RF sputtering system, a gold room with an aligner and spinner, and most of the chemicals I need for photolithography. Right now, I'm just having...
  6. U

    HTSC electron attraction

    That's my mistake. I've just become so accustomed to associating Type II with HTSCs that I've absent-mindedly used the terms interchangeably - something I probably need to watch out for while I'm writing my thesis.
  7. U

    FET simulation software

    Any luck?
  8. U

    HTSC electron attraction

    I was aware that the theory describing the mechanism of conduction in type II superconductors is still being debated - for some reason I thought I read somewhere that this type of attraction still held true in type II (HTSC). That's alright. I'll probably be doing a brief description of type I...
  9. U

    FET simulation software

    Much appreciated.
  10. U

    HTSC electron attraction

    This has been discussed to death around here I imagine - Cooper pairs and whatnot - so I'll try to be specific and not ask too broad of a question here. I did a little work with superconductors and I'm working on a passage for my thesis. I'm trying to provide background on Type I and Type II...
  11. U

    FET simulation software

    Yep. I'm trying to fabricate a transistor. I was looking for a simulator to try to verify the computations I did by hand for current density, gain, threshold voltage etc. I was looking for a software that I could actually enter the gate/source/drain dimensions/conductivities and the substrate...
  12. U

    FET simulation software

    If spice allows you to layout a transistor I wasn't aware. Have you ever simulated a transistor by drawing the gate/source/drain on a specifically doped substrate using certain metals for schottky/ohmic contacts? I'll check out spice, but I was thinking I would need something along the lines...
  13. U

    FET simulation software

    I'm a little outside my area of expertise here - I've used ADS to exhaustion, but now I need to simulate a MESFET I designed. Anyone have any recommendations for software? Our computer labs have quite a bit, but if there's a nice free/lite version that would be ideal. Thanks in advance.
  14. U

    On Solder and Superconductivity

    I've found some silver paint and silver/gold extender from Ted Pella (part number 16032 and 16021) - are you familiar with these and do you think they'd work? I'm not exactly sure how to apply the extender...the documentation they have on their site says that the paint hardens in seconds. That...
  15. U

    Variation between S11 and S22

    I've rotated the jig that the resonator is in which effectively causes S11 and S22 to switch. This is just the room temperature measurement. I'm dealing with HTSC material so the S-parameters should be significantly different after I cool the chamber. But you have to calibrate the...
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