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Electronics => General Electronics => Topic started by: lifeguard on July 24, 2016, 03:05:47 03:05



Title: Bias-T - how to calculate?
Post by: lifeguard on July 24, 2016, 03:05:47 03:05
Hi!
Is there any online tool or formula to calculte inductor and capacitor for Bias-T? I would like to build a Bias-T power insert to feede DC to my LNBF, with runs on 12~20v DC and frequency that I plan to use is abiut 1.5ghz (L-Band). How can I calculate the correct inductor and capacitor for this?
Just to be clear: I want to build Bias-T for power insert at receiver side, not LNBF (which alread has Bias-T internal).

Tks!


Title: Re: Bias-T - how to calculate?
Post by: bobcat1 on July 24, 2016, 08:43:32 08:43
Hi Lifegurard

Coilcraft is manufacturing special inductors for bias-T  seach there site for design application note and more information

All the best

Bobi


Title: Re: Bias-T - how to calculate?
Post by: bigtoy on July 28, 2016, 05:11:56 05:11
There's a calculator here; don't know if it meets your needs:
http://k6vhf.com/bias-tee-calculator/


Title: Re: Bias-T - how to calculate?
Post by: lifeguard on July 28, 2016, 12:40:10 12:40
There's a calculator here; don't know if it meets your needs:
http://k6vhf.com/bias-tee-calculator/

Tks!
I found this calculator a couple of days. How do I choice ratio? I mean, When I choice 10, 100, 1000? How this will affect bias-t working or attenuation?


Title: Re: Bias-T - how to calculate?
Post by: vern on July 28, 2016, 12:53:34 12:53
Here is another one, you just have to pick an amplifier with the right current
http://www.changpuak.ch/electronics/mar_era_bias.php (http://www.changpuak.ch/electronics/mar_era_bias.php)


Title: Re: Bias-T - how to calculate?
Post by: lifeguard on August 03, 2016, 11:05:55 23:05
Here is another one, you just have to pick an amplifier with the right current
http://www.changpuak.ch/electronics/mar_era_bias.php (http://www.changpuak.ch/electronics/mar_era_bias.php)
That's a great tool! Very usefull when you're building you amp. But in my case, I'm using an LNBF and I don't have any idea what kind of Amp and model are in. It's an dish LNBF, more specific a Titanium LNBF for C-Band.


Title: Re: Bias-T - how to calculate?
Post by: vern on August 09, 2016, 10:31:16 22:31
on the Titanium web site there is the C1PLL-C band LNBF, it says in the datasheet current 145mA max.
With the bias calculator take the LHA-1H+ amplifier, it uses 108mA, it is the highest value in that calculator.
If you have the resistor value for that one just take off about 25%, that should be the right resistor value for 145mA.