[time-nuts] Acitve GPS antenna biasing

IVAN COUSINS ijcousins at verizon.net
Fri Oct 9 13:58:43 UTC 2009


For a broad band, surface mount biasing inductor I use the Minicircuits 
TCCH-80.
The pin 1 goes on the microstripline.
The pin out has to be looked at carefully because the connections as 
viewed from the top and bottom do not connect straight through the multi 
layer ceramic base.

John

SAIDJACK at aol.com wrote:
> Hi Bruce,
>  
> these are very nice indeed.
>  
> I used these conical inductors in our 2004 FireFox broad-band  synthesizer 
> prototype (working from DC to 1.64GHz), they are quite  amazing.
>
> But:
>  
> * you need a microscope and a VERY stable hand to solder them down, and  
> cut-off the unused wire. I damaged quite a few before I figured out how to  
> solder them. And once soldered, they need to be physically protected because  
> they are so extremely fragile
>  
> * if I remember correctly they won't sell to everyone due to military  
> applications (their main use)
>  
> * their current handling capacity is limited
>  
> * And they are very expensive.
>  
> I ended up designing the FireFox with a series connected bias-t using a  
> 120nH inductor in series to a 150 Ohm power resistor in series to a 2.2uH/270  
> Ohm resistor combination.
>  
> That works very well up to over 1.6GHz, and costs pennies  compared to $$.
>  
> bye,
> Said 
>  
>  
> In a message dated 10/8/2009 19:33:06 Pacific Daylight Time,  
> bruce.griffiths at xtra.co.nz writes:
>
> For  broadband use a powdered iron filled conical choke such  as:
>
> http://www.piconics.com/BC/bc.pdf
>
> May be more useful,  provided it is oriented correctly with respect to
> the microstrip  transmission  line.
>
> Bruce
>
>
>
>   



More information about the time-nuts mailing list