Pre -amplifier验证预算方案

A目的：

SPF5189,SPF5122,SGA8543,RF2312在GAIN，OUT-POWER,ACPR, Harmonics ,Intermodulations,NF等方面特性

B需要设备：

DC power supply , signal generator , frequency spectrum analyzer , VNA

C power supply analyze

通过LDOLT1963供给的amplifier一共有四路，分别是SPF5189,SPF5122，SGA8543，RF2312.这四块chip需要的DCbias分别为

1 .SPF5189 : Flexible biasing option DC5V-DC3V, Adjust current(120mA)

2. SPF5122 : Flexible biasing option DC5V-DC3V, Adjust current(120mA)

3. SGA8543:DC3V3-DC2V7, Adjust current(max 105mA)

4 .RF2312 : DC5V-DC12V , Adjust current(125mA)

After studying LDOtheory and LT1963 datasheet , we can find the conclusion as below:

由于Iadj同温度是相关的，但具体的相关表达式我们无从知道，因此可以由上述equation得到：

1 对于DC5V，R1=1K,R2选择在2.2K-3.6K之间。即

2 对于DC3V 或者3V3  R1=1K,R2选择在

3对于DC2.7V, R1=1K,R2选择在

 4对于DC12V, R1=1K,R2选择在

D 验证步骤：

1 验证在整个band 内amplifier是否stability？

  Designing stable circuit 使amplifier unconditional stability

2 tuning bias ,in order to search the perfect status to satisfy efficiency , max-outpower,min-NF and so on.

3 measure the S parameter and study the relation between available gain power and DCbias

4designing matching network5 suppressing adjacent power according to tune relative element value of matching network and RF-power cross to DC power supply

6 compare four parts and lead to different Gain ,max out-power ,Noise figure, harmonics ,intermodulation and other performance under the same condition for chain.

下期blog,将会对这四款chip在端接50Ω时的参数进行测试分析，敬请关注！