5 ms·

You can create some pretty high frequency transistors (BJTs) with Indium Phosphide (InP) (ft > 600GHz, fmax > 1THz). See page 33 of: http://www.ece.ucsb.edu/F

You can create some pretty high frequency transistors (BJTs) with Indium Phosphide (InP) (ft > 600GHz, fmax > 1THz). See page 33 of: http://www.ece.ucsb.edu/Faculty/rodwell/publications_and_presentations/publications/2012_10_15_Oct_rodwell_CSIC_talk.pdf http://www.ece.ucsb.edu/Faculty/rodwell/publications_and_pre... ...for examples of some 600 GHz circuits, and: http://www.semiconductor-today.com/news_items/2014/OCT/NORTHROP-GRUMMAN_311014.shtml http://www.semiconductor-today.com/news_items/2014/OCT/NORTH... ...for a >1THz circuit using InP HEMTs.

raverbashing 10y ago
Wow that's crazy. I wonder how you even test a 1THz amplifier. Also what kind of natural noise might exist in those bands
- GregBuchholz 10y ago
  >I wonder how you even test a 1THz amplifier. Most likely using a mixer or some other non-linearity to down convert into the frequency range of your spectrum analyzer.
  - raverbashing 10y ago
    And how do you get the 1THz signal in the 1st place? Maybe upconvert as well?
- jpmattia 10y ago
  > I wonder how you even test a 1THz amplifier. The usual schtick is to measure the S-parameters a slower speeds and extrapolate out to the cutoff. (see chart 21 from the link above: http://www.ece.ucsb.edu/Faculty/rodwell/publications_and_presentations/publications/2012_10_15_Oct_rodwell_CSIC_talk.pdf http://www.ece.ucsb.edu/Faculty/rodwell/publications_and_pre...) For the digital people, building a ring oscillator with N stages will cause the output to divide by N, and just make sure that f/N is in the range of your oscilloscope. To actually measure things up in the THz range directly, there are more exotic methods: Superconducting bolometer is one that I've been involved with. But those are a PITA for a bunch of reasons.
pbhjpbhj 10y ago
Does 'Heisenberg' or some other theory limit the top frequency, if so, what's the limit?

raverbashing 10y ago

Wow that's crazy. I wonder how you even test a 1THz amplifier. Also what kind of natural noise might exist in those bands

GregBuchholz 10y ago
>I wonder how you even test a 1THz amplifier. Most likely using a mixer or some other non-linearity to down convert into the frequency range of your spectrum analyzer.
- raverbashing 10y ago
  And how do you get the 1THz signal in the 1st place? Maybe upconvert as well?
jpmattia 10y ago
> I wonder how you even test a 1THz amplifier. The usual schtick is to measure the S-parameters a slower speeds and extrapolate out to the cutoff. (see chart 21 from the link above: http://www.ece.ucsb.edu/Faculty/rodwell/publications_and_presentations/publications/2012_10_15_Oct_rodwell_CSIC_talk.pdf http://www.ece.ucsb.edu/Faculty/rodwell/publications_and_pre...) For the digital people, building a ring oscillator with N stages will cause the output to divide by N, and just make sure that f/N is in the range of your oscilloscope. To actually measure things up in the THz range directly, there are more exotic methods: Superconducting bolometer is one that I've been involved with. But those are a PITA for a bunch of reasons.

pbhjpbhj 10y ago

Does 'Heisenberg' or some other theory limit the top frequency, if so, what's the limit?