Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would
be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate
that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views.
It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if
you would like to post something on RF Cafe's
page, please do.
Below are all of the forum threads, including all
the responses to the original posts.
Post subject: Mini-Circuits Coaxial Amplifiers Supply Voltage?
Posted: Fri Jul 17, 2009 5:46 pm
Jul 17, 2009 5:42 pm
How critical is the supply voltage
(15VDC or 24VDC) on Mini-circuits 50 Ohm Coaxial amplifiers?
5 to 500MHz
10 to 1000MHz
10 to 2500MHz
can't give me a spec they just say - "any well-regulated low-noise power
supply". The Project Manager/Scientist where I work wants me to spec
something to power these that has the same specs as Laboratory bench
top grade variable power supplies with line and load regulation <0.01%
of maximum output and ripple and noise <10mV P-P (constant voltage
mode). But I'm not so sure if they have to be that good?
Post subject: Re: Mini-Circuits Coaxial Amplifiers
Supply Voltage?Posted: Sun Jul 19, 2009 2:52 pm
Joined: Mon Jun 27, 2005 2:02 pm
There is a good applicaiton note provided
by Minicircuits regarding the bias requirements for amplfieirs, although
this document applies to IC's (MMICs), it would also be relevant for
In general, for RF amplifiers it is important to provide a low noise
supply voltage, as any noise on the supply voltage can be easily coupled
to the RF signal.
for a 15VDC and above supply <10mVPtP ripple
and noise requirement is not easy to achieve.
A good design
practice is to use:
1. Low-noise LDO with several bypass capacitors
(having different values).
2. RFC (RF Choke) connected between
the RF output of the amp to the supply. Its value should give several
hundreds of ohms at the lowest frequency of operation.
The SRF should be higher than the highest frequency of operation.
3. You can also use Ferrite Bead connected between the supply
voltage and the bypass capacitors. It will help to absorb and reduce
radiated and conducted noise. It is important to choose the right one
in terms of frequency range and impedance.
Re: Mini-Circuits Coaxial Amplifiers Supply Voltage?Posted: Wed Aug
05, 2009 11:35 pm
Joined: Wed Aug 05, 2009
Thanks for sharing this useful information.
plan solution commission de surendettement
- commission de surendettement, vous pouvez demander un dossier de surendettement.plan
solution commission de surendettement
Post subject: Re: Mini-Circuits Coaxial Amplifiers Supply Voltage?Posted:
Wed Aug 12, 2009 11:28 am
Joined: Fri Jul
17, 2009 5:42 pm
Thanks for the reply and
for the information, it was very helpful.