I/Q frequency ramp signal generation

[ansi512]

Hello NI,

for an FMCW avalanche radar, we are looking for a signal generator on PXI basis.

The waveform we use is a frequency ramp signal from 0 to 200 Mhz followed by the reverse direction from 200 to 0 Mhz. Each chirp (the complete ramp are two chirps called up-chirp and down-chirp) has a duration of 4ms, so the full sequence will be about 8ms. We need an I/Q signal to feed into the radar transmitter unit, that is a two channel signal with channel Q being 90° phase shifted to channel I. The signal level p-to-p is about 1V from -0.5 to 0.5 V, however, the radar works apparently best if the Q channel has a slightly shifted level against the I channel

Which PXI device can you suggest for my purpose?

I see the pxie-5450 that produces directly an I/Q signal, however, I don't really get the datasheet sayings about the maximum frequency that the device can deliver and if the above mentioned waveform (frequency up followed by down ramp) can be achieved.

I see the bandwidth to be 145Mhz, so we may live with that compared to 200Mhz by sacrifying some range resolution. But the datasheet says something about 0.4xI/Q rate (=58Mhz) and 0.8xI/Q rate (=116Mhz) which would be definitively to small. Any comments on that?

Thank you very much,

Anselm Köhler