Re: MMIC's

Colin Ranson

Hi Geoff,


Ha !   waiting for a couple of 35mm (or so) pipe caps to make a 2556MHz filter. I hope to align these using a noise source and my SAA-N2 VNA.  Wonder what size caps you used ? I have some 28mm here so it might be a toss-up between the two sizes.


Glad to see people on the RF make !


73’s   Colin.


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From: geoffrey pike via
Sent: 08 January 2021 17:47
Subject: Re: [UKMicrowaves] MMIC's


Hi Colin,

Doing somethimg similar just to do something!, anyway DDK microwave source pcb 103.5 MHz Xtal output at 1242 MHz (this has needed a job so iam using it), this drives a MCL VNA-25 mmic at about 4dBm this then goes into a pipe cap filter at 2484 MHz, then another VNA-25 with -8dB ahead of it to give 14dBm at 2484 Mhz then into the W1MHZ quadrupler for about 8 dBm out at 9936 MHz to drive a Minicircuits mixer and mix with 432 MHz. The VNA-25 is a small outline 8 pin DIL device so a bit different to usuall mmic. About 14 dB gain and 17dBm out at 2,5 GHz. 





On Friday, 8 January 2021, 14:03:52 GMT, Colin Ranson <g8lbs@...> wrote:



Hi all,


I have repurposed a DDK 2008 L band source from 96MHz to 106.5MHz with an output of 1278MHz.  The original was extended to include a PGA103+ to bump up the output to feed a high level mixer.   



Thinks ?  could I use this MMIC as a doubler to 2256MHz ? I understand from texts that it has to be operated in a non-linear fashion)  At the moment its biased to 3.5v and I have removed a level determining attenuator so I am hitting the MMIC quite hard. I am detecting very little at 2556MHz at the moment. (not enough to drive my Qualcom x 4 multiplier to 10.224GHz)


Can anyone give me a ballpark figure to set the bias to please ? And is this likely to work well enough ? I have not tried this method before so hopefully with enough 2256MHz I will include a ‘stop-end’ filter and enough gain to give me 3dbm at the Qualcom Mult input. Getting the 10dbm output (after filtering) for the mixer(s) will be another matter.


Best regards to all, keep those soldering irons hot !


Regards, Colin de G8LBS.




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