As I can see from the PXI3-5673's specification(Page 15), it only provide the IMD3 performance of two tone signal with 300KHZ apart. How about the IMD3 performance when the two tone signal is 1MHZ,5MHZ(let's say 1M~10MHZ) apart? Is there any data?
And what's the Intermodulation intercept point(IP3) of this product? If we calculate the IP3 base on the PXI3-5673's specification(Page 15), see following:
1.two tones, 300 kHz apart, at –6 dBm per tone)
LO Frequency
(two tones,
300 kHz apart,
at –6 dBm per tone) | |
| 3.3 GHz to 6.6 GHz | –43 |
IP3=Pout+|IMD3/2| = -6 + |-43/2| = 15.5 dbm 2.two tones, 300 kHz apart, at –36 dBm per tone) | |
LO Frequency
(two tones,
300 kHz apart,
at –36 dBm per tone) | |
| 3.3 GHz to 6.6 GHz | –51 |
IP3'=Pout+|IMD3/2| = -36 + |-51/2| = -10.5 dbm
As I known, the IP3 of the same device should be the same regaless of the input power level. But, why I get such a big different IP3s base on the data of the specifiction?
