🚀 go-pugleaf

On Fri, 11 Jan 2002 13:31:31 +1100, Russell Shaw <rjshaw@iprimus.com.au>
wrote:

>
>
>Spehro Pefhany wrote:
>> 
>> In sci.electronics.design Russell Shaw <rjshaw@iprimus.com.au> wrote:
>> 
>> > I need to make small resistors (10-200ohms) operate at a
>> > few GHz, and so be non-inductive/capacitive. I can do it
>> > by depositing carbon paste with a stencil.
>> 
>> You should be able to buy this stuff from the makers of inks for
>> thick-film hybrids. You can silk screen it on (control of viscosity,
>> pressure and squeegee angle and spacing from the substrate are all
>> important in controlling the thickness). Then it is "fired" at a high
>> temperature. You can trim said resistors with abrasive or lasers.
>> 
>> Is it really such a big deal with regular resistors? I can't imagine an
>> 0402 or 0201 resistor 10-200R resistor having much inductance or
>> capacitance at those frequencies.
>
>Various resistors use a 'zig-zag' of thin track, which may
>get inductive relative to 10ohms at a relatively low
>frequency compared to a carbon composition one.

 The resistors that Sphereo mentioned are surface mount on ceramic
substrate.  I have used these in sampling circuits that required 120ps
sampling pulses.  The parasitic attributes of resistors did not give me
any trouble. 


Regards,

Boris Mohar

VIATRACK Printed Circuit Designs