Pout: output power

IM3: third-order intermodulation product

IIP3: Enter the third-order intercept point.

OIP3: Output the third intercept point.

G: gain

P 1dB: 1dB compression point

Answer: The difference between output power and IM3.

For RF amplifiers, IF amplifiers, mixers and other devices, OIP3 is generally larger than p 10 ~ 15dB 1dB.

2 the mathematical relationship between indicators

The mathematical relationship between indicators is as follows.

pout(dBm)= Pin(dBm)+G(dB)( 1)

OIP3 (dBm) = IIP3 (dBm) + G (dB) (2)

OIP3 (dBm) = Pout (dBm) +A/2 (dBc) (3)

IIP3 (dBm) = Pin (dBm) +A/2 (dBc) (4)

IM3(dBm)= 3Pin(dBm)–2 ip3(dBm)+G(dB)

= 3 Output (DBM)–2IP3 (DBM)–2g (DB)

= 3 output (DBM)–2 input and output 3 (dBm) (5)

3 application

When the output signal Pout of a device is smaller than P 1dB 1dB, the value of a (OIP3 is generally larger than p 10/5dB).

According to formula (3), a is between 40 and 50 DBC.

When the output signal Pout of a device is 20dB smaller than P 1dB, the value of a (OIP3 is generally larger than p 10/5 db).

According to formula (3), a is between 60 and 70 DBC.