Identify this transistor?

[z3phyr]

Hi all

I'm having a hard time identifying this transistor. From the circuit function and layout, I figured that it is an oscillator working around 2 GHz. There is a little piece of transmission line connecting the gate to ground. The drain is biased at 2.5 V and the source is pulled down to -1V or so to turn on the transistor, and then oscillation starts until the source is returned to ground.

Any help is appreciated!

 

[albbg]

From the picture I can't read the marking code. What code is written on the transistor ?

 

[z3phyr]

I think it's either "On" or "Oh"

 

[albbg]

Have you got a more clear picture of the component ? However it seems to be a diode, since it's labelled as D6.
Sorry I saw now the component is the white one.

 

[z3phyr]

Yeah the white one is what I'm talking about. It is labeled Q1.

I'll try to take a better picture; need to find a better camera...

 

[BradtheRad]

I believe it's a microwave transistor. Example, MRF-901.

Your picture shows it's round with 4 terminals. Almost exactly like the transistor in this thread:

https://www.edaboard.com/threads/236020/

 

[D.A.(Tony)Stewart]

WHen you figure out the orientation and the numbers or letters , look up here for SMT transistor markings

https://www.digikey.com/classic/doc...CC_353/PDF/MCC_SMD_Marking_Codes.pdf&curr=USD

 

[D.A.(Tony)Stewart]

JUst a common list supported by one company.

Here's a more complete book of codes
https://www.electroschematics.com/wp-content/uploads/2013/04/SMD-code-book.pdf

 

[z3phyr]

This is weird. I can swear I didn't post the following

7A MMBR901 Mot N SOT23 npn RF MRF901

THe photo looks more like something else 4D?

 

[D.A.(Tony)Stewart]

It was my oops.

I'm almost certain that the transistor in the circuit that I showed is a MOSFET. The MRF-901 seems to be a silicon NPN?

7A MMBR901 Mot N SOT23 npn RF MRF901

THe photo looks more like something else 4D?

Will the real ID code please be given?

 

[Terminator3]

This transistor may be outdated, not produced anymore. Do you want replace or copy design? I would use some vco chip or s53mv's parallel feedback oscillator.

 

[ledum]

Khm, it looks like http://www.ciel-electronique.com/el...uctors/NE85635_High-frequency-transistor.html
or

or

NE85635 - bipolar transistor. "h" and colour mean a lot number.

 

[z3phyr]

Interesting find!

The schematic shows it as a FET. But maybe the final circuit was assembled using a different part. And maybe that's why the final circuit doesn't look quite the same as the schematic.

Khm, it looks like http://www.ciel-electronique.com/el...uctors/NE85635_High-frequency-transistor.html or **broken link removed** or **broken link removed** NE85635 - bipolar transistor. "h" and colour mean a lot number.