H-MODE HIGH LEVEL SWITCHING MIXERS FOR HF WITH FST3125M IC
|IT CAN ACHIEVE AN OUTSTANDING IIP3(input IP3) around
+40dBm to + 42dBm equal to an OIP3 (output) of +35 to +37 dBm with 5dB of insertion
loss in the HF range and IF
at 9MHz (for input signals level range up to +5dBm). Isolation between ports is good
and OL power required is around 0 dBm and +5dBm much less than for passive high
level diode mixers. DO NOT LEAVE Floating the LO input when powering ON
board. With AC SOIC IC logic Total Power Supply Current, with LO generator connected with signal at 0 dBm, is around 22 mA at 5,000 Volt.
A Doubly Balanced "H-mode"
Mixer for HF "
By Sergio Cartoceti, IK4AUY
July/August 2004 QEX (ARRL ) Magazine, pages 23 - 32
(reproductions only with permission: copyright ARRL, QEX July/August 2004, all rights reserved). This material originally appeared in QEX:Forum for Communications Experimenters
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More remarksabout “A Doubly Balanced “H-mode” Mixer for HF “ article:
About other frequency ranges: in spite i intended to use this RF Mixer with 9 Mhz IF and an RF input from 1.8 to 30 Mhz this mixer works upto more than 100 MHz with 43 type binocular baluns specified, but not tested it for IP3 or ports attenuation balance in that range, and insertion loss could be around 6 or 7 dB instead of around 5 dB (still comparable to a passive mixer). Use AC faster logic 74AC86 (NOT 74HC86 maximum usable up to 50 Mhz).
Murata datasheet for LCL (5 Volt power supply filter which was not specified in component list but not critical) EMI FILTER Suppression, 3 terminal, could be a MURATA DSS series straight type with built in ferrite beads with 10.000 pF 100 V (suffix ending with 103) (or better a 22.000 pF 16V, suffix ending with 223)
catalog at http://www.murata.com/catalog/c31/es0150.pdf
A large stocking component distributor I use in Europe is Farnell (also for FST3125 IC)
(its Murata catalog in http://www.farnell.com/datasheets/6821.pdf)
have also tested a smaller pcb 51 mm X 36 mm (unpublished
for lack of space in the magazine):
Last update: Nov 25, 2009.