Need wide frequency balun transformer ?
For a new design i need a balun transformer for frequency range 10MHz
to 3GHz -low power (20dbm max)
Any one know where to buy or how to make one
Thanks
Bobi
This is a pretty broad range. You might look at T/o/k/o 617DB-1022, 617DB-1024 or M/A-C/O/M ETC1-1-13
You will have trouble finding a balun for such a wide frequency range. It will take two or more to cover this range.
You should reconsider the block diagram of your system to make it into several frequency ranges.
To realize a balun transformer within a very wideband frequency range, it should be noted that simple classic L-C baluns can not cover this frequency band.
There are two ways to realize it.
1-Using a transformer which has tight coupling coefficient and one of the output pins is grounded. In this way a well designed transformer will behave a balun.
But transformer losses and especially low frequency response must be optimized. If you increase inductance value of primer side to hold low frequency behaviour , self resonance frequency of the primer inductance will drop in frequency of interest.( sure)
2- Using ferrite double aperture transformer. In this method losses will be higher than but low frequency response might be better controlled.
In my opinion using Epcos( formerly siemens-matsuhita ) transformers is better. Because to find ferrite with the same characteristic and production within a same relibility is much difficult.
In this way , there are some restrictions such as frequency response may not be flat as desired and impedance ratios can change by frequency.
Indeed design a balun transformer that will work in very wide band frequency range is really difficult.
If you design transformer by hand,I think it hard to get tight couple up to 3Ghz because an operatable volume.
By the way,Ferrecube(former Philips) has some good high frequency soft magnetic material.
M/i/n/i/c/i/r/u/i/t/s RP-2-30 covers 10MHz to 3GHz. Its on their website.
Can't find the minicir RP-2-30 or any Data sheet regardig this
transformer perhaps the name spelled wrong
Is it a balun transformer I need 50 to 200 ohm impedance converter
can you place link to the data sheet
thank you
bobi
There are a few 1:4 impedance ratio transformers at Minicircuits, but the widest BW what I found is 10-1900 MHz (3 dB BW). Check at their website ( part TCM4-19), or youcan use the link:
http://www.minicircuits.com/cgi-bin/...l=TCM4-19&bv=4
regards, Al