Question about Downconversion Module LTC5510

Hi,


We are seeking for :

1) An analog upconverter module to upconvert a 1GHz bandwidth signal from an IF at 1.5 GHz to an RF at 5 GHz. It also needs to provide an output voltage swing of 1.125 V(p-p) with an input of 1V(p-p)at the IF port(1.5GHz).

2) An analog downconverter module to downconvert a 1GHz bandwidth signal from an RF at 5 GHz to an IF at 1.5 GHz. It also needs to provide an output voltage swing of 1V(p-p) by using an input of 300 mV(p-p).


We have noticed that LTC5510 (1MHz to 6GHz Wideband High Linearity Active Mixer) meets our needs assosiated with the bandwidth and frequency range. However, the conversion gain of 1.5dB is not sufficient to provide the required output voltage level of 1V p-p by using an input of 300 mV (p-p).

Can anyone recommend an appropriate solution from analog devices that fulfills the voltage level requirements for this set of IF/RF frequencies.?

Thank you in advance.


  • Required RF gain is 20*log(1V/0.3V)=10.5dB. Gain of selected mixer is typ. 1.5dB thus you need RF gain block with G=9dB. If NF is critical parameter, the RF gain block shall be in front of mixer. Otherwise for better linearity RF gain block (with high linearity) is suitable to place at IF port. Did you check the mixing products? For example in upconverter case assuming the LO is above RF, spur 3*f_in = 3*1.7GHz≅5GHz may cause the problem especially when the input level is near 1dB-compression point. And similar e.g. for product f_LO - 2*f_input.

    The RF level is specified for upconverter using 4 digits 

    1.125 V

    This is quite accurate. I am not sure, but over band 5GHz ± 0.5GHz I would expected at least 1dB ripple.