I'm comparing a couple of GNSS front-end modules. Is a lower In-band IIP3 point better or worse than a higher one?

Question

I would typically compare the small signal gain and noise figure first. One of the FEMs requires an external matching component but other that they are very similar in terms of cost and foot-print size.

I reviewed this website tutorial on the differences between -1dB compression and 3rd order points but still not sure how the point (-9dBm or -7.3dBm) will ultimately affect the performance or linearity of the amplifier.

[ SKY65903-11[2]

These two choices have almost identical NoiseFigures, and are quite close on the IP3 ---- 1.7dB is about 1.5 (50%) more interfering power. I'd pick the one needing NO external SMTs. — analogsystemsrf, Mar 17 '17 at 03:46

score 1 · Accepted Answer · answered Mar 16 '17 at 19:04

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The higher the better (other things equal), because more input power will be needed for the same amount of degradation in linearity. So you will have better dynamic range.

Also, intermodulation noise can reduce your effective \$E_b/N_0\$, thus increasing your bit error rate (BER). The sensitivity of your receiver will decrease.

answered Mar 16 '17 at 19:04

Enric Blanco

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Thanks. YEah in the product where this FEM will be used, we also have a lot of noise so I'm sure the CNo will also decrease. – Samee87 Mar 20 '17 at 19:07

I'm comparing a couple of GNSS front-end modules. Is a lower In-band IIP3 point better or worse than a higher one?

1 Answers1