could some suggest some tips for designing layout for this circuit?like track width,type of pcb,track length,placement of components.
uhf tx layout
could some suggest some tips for designing layout for this circuit?like track width,type of pcb,track length,placement of components.
Go get an ARRL Radio Amateur's Handbook (any year) and read the VHF chapters. You might be able to borrow one from a local ham or the library.
Last edited by MikeMl; 9th June 2009 at 09:31 PM.
The thumbnail gives a pretty good basic layout for the parts and trace routing.
Make trace widths minimum to minimize capacitance (except for the connection from the output transistor to antenna as shown).
Lay out to minimize trace lengths.
Make sure to add the vertical grounded copper screen (shield) shown between stages to minimize the chances of oscillation.
Use a ground plane on the component side of the board as shown.
Connect all decoupling capacitors directly to the ground plane (surface mount caps are best)
And, as with all HF circuit design, good luck.
Carl
Curmudgeon Elektroniker
I would stress that you should follow the layout and components given by the inventor/author. The components are likely tweaked for the circuit to operate best based on that layout.
Your board would best work using a microstrip layout. Trace width should be chosen based on impedance. In your case I think 75 ohm. Read up on microstrip, and you can also get some info here.
Microstrip Transmission Line Characteristic Impedance Calculator Using a Formula by Brian C Wadell
And more theory here.
http://www.ansys.com/industries/mems..._micostrip.pdf
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