LNA, frequency mixer and oscillator

Hi all,

I have a USRP2 and a BasicRX. I am new to GNURadio and I am still
learning. I have successfully tested the USRP2 with BasicRX. What I
have read so far the BasicRX is capable of receiving RF signals from
1-300MHz. But on the FFT window generated by the GRC, it will only
display up to 100MHz, limited by the maximum samples. I have searched
through the discussion list that the frequency is wrapped and the
BasicRX needs a frontend RF circuit.

Basically I will need a LNA, a frequency mixer and an oscillator. To
my understanding, if I multiply the RF input signal with 100MHz, the
whole band ranging from 100MHz - 200MHz will be brought down to
0-100MHz. So I can display it to the FFT window. If I want to scan
200MHz-300MHz, I shall multiply the RF signal with 200MHz. Please
correct me if I’m wrong.

I have been browsing minicircuits to get the parts needed and I’m not
sure if I got everything right. As for the LNA, I have the ZFL-1000LN+

For frequency mixer, I have found the ZFM-3+

For oscillator, I have found the ZX95-200+

Are these components correct and enough for me to build the RF frontend?

Thank you for your answers.

Ahmad Zaki Yaacob


you are correct about the downconversion of the RF signal, about the
circuit component i hope you got it from some advisors or some
tutorials, for mixer you can also consider Gilbert cell frequency mixer
which has good performance