Help finding documentation on YIG driver Teledyne FSD2637C YIG oscilator

Thread Starter

yef smith

Joined Aug 2, 2020
717
Hello,I got the YIG device Teledyne M/N FSD2637C-F-DA,
I like to connect and test this device ,but there is no driver schematics on the website or how to power the input so the YIG device will properly function.
Could you please help me with documentation (schematics ,application notes,how to input the device)for this model?
There is no such model in te website link bellow.
If anyone worked with this model or similar one ,how do i properly power such or similar device?

Thanks.
https://www.teledynedefenseelectronics.com/wireless/YIG Products/Pages/YIG Oscillators.aspx
 
Last edited:

n6ac

Joined Apr 29, 2011
6
Hello Yef – About 50 years ago, I worked with Yig-tuned oscillators as part of (phase locked loop) microwave frequency synthesizers. I assume they are still similar – the coil needs to be driven by a controlled current source. So, for example, the YIG coil was driven from collector of bipolar transistor whose current is sensed in emitter (or drain of MOSFET with sensing from drain). Added inductor in emitter (or drain) leg to decrease noise, arranged for temperature compensation of changing copper resistance, I can't remember exact circuit trick I used.
Note I am talking of the YTO – no idea of what the extra circuit board in your photo is.
 
Last edited:

jeffl_2

Joined Sep 17, 2013
74
Yes I too remember working with YIG-tuned oscillators to build high-performance microwave synthesizers ALSO a very long time ago, the one I worked on was to be the LO for the down-converter for a microwave noise analyzer, but this was SO long ago that I can only make qualitative contributions to the discussion. What you have here is an oscillator whose frequency can be "steered" over a great range by changing the strength of the magnetic field, this should teach you a couple of things, first of all just rotating the position of the unit in the room will change the emitted frequency without ANY field or special driver, so you may want to consider adding additional magnetic shielding to the box. Secondly there are two coils so you can do fine and coarse tuning in separate circuits, but in either case the current loop has to be pretty darn low noise (equivalent to say a professional microphone preamplifier stage) or else noise in the coil driver translates into frequency modulations, and these frequencies are SO high that the FM can quickly escalate into several megahertz or more (it used to be called "phase noise")! And you also probably want to drive that coil current driver from the phase detector of a phase-locked loop, and at these frequecies you probably want to look around the internet for the operation and block diagram of a fractional-N PLL to increase the frequency resolution and further lower the noise propagated around the PLL's loop. So in conclusion there isn't so much about the "YIG" part that's really unique as there is need for careful control of magnetic fields, and low-noise current driver circuits and a robust loop design. Happy YIG'ing!
 
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