On 11-12-2011 13:29, Doug White wrote:
clifford wrote in
:

Anyone had experience of using mimic's as post diode balanced mixer
amplifiers?
In theory they look OK, 50 Ohms in and out and good high level signal
handling. This is to be for a 45 MHz first IF.
Cliff Wright ZL1BDA

Assuming you have a decent filter after the mixer to extract the band you
want, the MMIC amps work fine. However, I'd be wary of any recent Avago
parts. The data sheets can be very inaccurate, and the parts may not
behave as advertised. I've had very good luck with NEC, and a lot of
MiniCircuits amps are decent as well. RFMD also has some nice parts. The
Avago parts that were actually designed when they were Agilent (or better
yet HP) are also good. If the parts are advertised as 50 Ohms in& 50 Ohms
out, there is a lot less to go wrong. The ones that require custom
matching networks take more care to get running right because of circuit&
component parasitics.

Doug White

When using the MiniCircuit MMICs, I recommend using the "optional" choke
between the device and its biasing resistor (as shown on device
datasheets). Without it, you can lose a few dB of gain. The value is
not critical. At 45 MHz, 5 or 6 turns through a VHF ferrite bead should
be enough. The MAR-4 is a decent choice unless you need more gain or
output level. The datasheets show gain and max power out (P1dB)...if
you want it to be linear, stay below that point. If you know the level
at 45 MHz and the level you want out of the MMIC, you can place a simple
resistive PI or T attenuator between your 45 MHz source and the MMIC,
then the output of the MMIC would be the level arriving at the MMIC plus
it's associated gain.
http://www.minicircuits.com

N0EDV