方案一：SGA8543

Condition:

1 freq=63.86MHz △freq=1MHz

2 bias Vd=3.0V Id=40ma

3 termination impedance=50Ohm

If Pout = 13dBm

The result is as blew:

Gain=33dB

Harmonic Distortion:

HMD2=-30dBc  HMD3=-36dBc

Intermodulation Distortion:

IMD3=34dBc

C Aggravation of Noise floor can be seen and compared Part a with Part b as blew:

 Part a Noise floor without DC bias

 Part a Noise floor with DC bias+3V

方案二：5189z

Condition A:

1 freq=63.86MHz △f=1MHz

2 DC bias Vd=4.0V Id=60ma

3 termination impedance=50Ohm

If Pout = 13dBm

The result is as blew:

Gain=25dB

Harmonics Distortion:

HMD2=-33dBc  HMD3=-48dBc

Or add the matching circuit to the back stage of amplifier chain:

HM2=-53 dBc ;HM3=-70 dBc

If increase Pin power 3 dB or decrease the same value, we can obtain information between fundamental and harmonics from graph as blew:

HMD2=-46dBc HMD3=-64.38dBc

Power input increased 3Db

HMD2=-57.56dBc ;HMD3=-75.52dBc

Power input decreased around 3dB

Refer to the intermodulations of this IC , details'll be displayed in the next blog .