When setting up and testing for the evaluation board of AD9371, I have some confusions that need to be clarified. The issues are as shown in the picture:
- In Picture_1, we used the FPGA settings to transmit a CW signal, the freq of the single tone is sweeped up from +1MHz. At the receiver, the spectrum peak moved up too until +60MHz. When we sweep frequency of CW to +62MHz, the spectrum peak is produced at the position of negative side as in the picture. Just wonder why it does like that, is there any real signal at that frequency or this is just an production of software display.
- In picture_2, we have set up for the transmitter to send a CW signal at 56MHz offset. At the receiver, the bandwidth is set at 10MHz. In my mind, I am thinking that the single tone is outside of RX BW, then it must be attenuated. However, the figure still shows a spectrum line with strong intensity.
Maybe we have set something wrong in the setup. Please clarify which parameter should we check more detail to explain this confusions.#