[hpsdr] QSD architecture and image suppression

[Bob McGwier]

Ahti Aintila wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> On 21/02/2008, Phil Harman <phil at pharman.org> wrote:
>   
>> ***** High Performance Software Defined Radio Discussion List *****
>>     
>
>   
>> On Penelope the image is > 80dB down, the limit of my measuring equipment.
>> On Mercury as long as the ADC is not overloaded then I can't see any image.
>> In which case it would be >110dB down.
>>     
>
> Very good, Phil!
> Now we need a power amplifier with IM and spurious emissions down more
> than 80 dB. A pretty tough job for EER amplifiers?
>   

We do not need to get IMD down that far to GREATLY exceed any available 
transmitter/transceiver on the market today.  If we get it 55 to 60,  we 
are kicking them down the alley by 20 dB in most cases.  I do believe we 
can make a 15-20 dB improvement over the best on the market with an all 
SDR implementation driver the high efficiency chain and the switching 
power supply modulator. 
> Ahti OH2RZ
>
>   

73's
Bob


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