Rohde & Schwarz FSW43 - Page 277

Measurements
R&S
®
FSW
277User Manual 1173.9411.02 ─ 19
Fig. 5-40: Intermodulation products Ps1 and Ps2
The intermodulation product at f
i2
is generated by mixing the 2nd harmonic of useful
signal P
U2
and signal P
U1
.
Tthe intermodulation product at f
i1
is generated by mixing the 2nd harmonic of useful
signal P
U1
and signal P
U2
.
f
i1
= 2 × f
u1
– f
u2
(1)
f
i2
= 2 × f
u2
– f
u1
(2)
Dependency on level of useful signals
The level of the intermodulation products depends on the level of the useful signals. If
the two useful signals are increased by 1 dB, the level of the intermodulation products
increases by 3 dB, which means that the spacing a
D3
between intermodulation signals
and useful signals is reduced by 2 dB. This is illustrated in figure 5-41.
Third Order Intercept (TOI) Measurement