I want to upconvert a square pulse of 250 Mhz bandwidth(250Mhz is the value of the first zero of the sinc ) to a center frequency of 4.25 Ghz , so that the spread becomes from 4Ghz to 4.5 Ghz.

Effectively, the output I want is \$ sin(2 \pi \cdot 4.25 \cdot 10^9 t) * Pulse \$.

Previously it has been done with a switching mixer HMC128 . From my understanding of switching mixer, it basically either allows the signal to pass as it is or blocks it depending on the phase of the Local Oscillator.

The problem is that the above IC is not available on any of the sites like Digikey etc that ship to India. Can any one suggest some other mixer? Also can anyone explain exactly how the switching mixer gives the output I desire? Is there some sort of filter to remove the multiplication of the harmonics of 4.25Ghz?

  • 2
    \$\begingroup\$ When you say the part is "not available", what precisely do you mean? Hittite shows it on their website, and does not show it as "discontinued" or "obsolete" or anything like that. \$\endgroup\$ Feb 1, 2012 at 1:31
  • \$\begingroup\$ I am unable to find a way to order 2-3 pieces that I need directly from Hittite to be delivered to India and sites like Digikey do not have it. Hence a substitute required. \$\endgroup\$
    – gururaj
    Feb 1, 2012 at 8:55
  • 4
    \$\begingroup\$ @gururaj: If you are a university student, and this is for a student project, email the company, explain that you are a student, and you need two or three for a school project. If you are not a student, the thing to do is email them and explain, POLITELY, that you need a small quantity of these units for prototype development. \$\endgroup\$ Feb 1, 2012 at 22:02
  • 3
    \$\begingroup\$ If you want to request samples, you might have more luck contacting Hittite's local sales rep, which is apparently Syratron (syratron.com). They might also be able to refer you to a local distributor. \$\endgroup\$
    – The Photon
    Feb 2, 2012 at 3:02
  • 1
    \$\begingroup\$ The lowest RF,LO f is 1.8GHz for this mixer. You might want to start looking for differently specced mixer but of the same type (switched). Still with mix of pulse video and GHz carrier the idea of using switching mixer looks valid \$\endgroup\$
    – user924
    May 28, 2012 at 16:16

1 Answer 1


THese devices are not stocked as they tend not to be in high demand. The factory also does not keep stock. So MOQ = 10 * $23.11 or so.= $231 + tax etc.

However if you consider a cross-over part with similar specs, http://www.minicircuits.com/pages/npa/SYM-63LH+_NPA.pdf This also has an MOQ of 10 but is less expensive. 10 x 12.95 = $130

Your choice.

Otherwise design a pin diode on a controlled impedance board to switch your LO with appropriate BP shaping filters.

Are you trying to jam with this band ? ♬ ⚡ !


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.