(b)

Input Power (dBm)

Input Power (dBm)

pb697d

Figure 6-85. Diagram of Gain Compression

Figure 6-86 illustrates a simultaneous measurement of fundamental gain compression and second harmonic power as a function of input power.

CHl Spi

100 NAG

.2 clE/ REF

10

dB

 

 

 

 

G A I N

OHPR

SSIOtj

I

 

 

I

I

I

I

1

 

I

I

I

 

I

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CHI S T A R T

- 5 . 0 dBnl

c w

i 2 0 0 . 0 0 0

0 0 0

HHZ STOP 1 0 . 0 dBrn

CH2 B

102 N A G

10

a24 R E F

- 3 0

dB

L

I

I

I

I

I

I

I

I

I

1

CH2 START - 5 . 0 dBm c w 1 2 0 0 . 0 0 0 0 0 0 MHZ STOP 1 0 . 0 dBm

Figure 6436.

Swept Power Measurement of Amplifier’s Fundamental Gain Compression and 2nd

Harmonic Output Level

In a compression measurement it is necessary to know the RF input or output power at a certain level of gain compression. Therefore, both gain and absolute power level need to be accurately characterized. Uncertainty in a gain compression measurement is typically less than 0.05 dB. Also, each input channel of the analyzer is calibrated to display absolute power (typically within +0.5 dBm up to 3 GHz, and + 1 dB up to 6 GHz).

Application and Operation Concepts 6-156

Page 436
Image 436
HP 8753E manual Diagram of Gain Compression