ADL5324 Input match S-parameters at 400Mhz

Document created by analog-archivist Employee on Feb 23, 2016
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I tested the ADL5324 at 400Mhz and find that its' input impedance varies
significnatly from the suggested network in datasheet to give 50ohm matching
(about 4.3ohm and the output impedance to be around 16ohm). With L-C matching
networks applied to give measured 50ohms and powering from 3.7V, the device
prematurely compresses compared to the datasheet.  Input powers (dBm) of
0,3,6,9,12 produce output powers of 17.7, 20.0, 22.0, 23.0 and 23.5
respectively.  Even with say +13dBm input I can only ever achieve 0.25W output
power at 400MHz.   Does this match you expectations for the device running
below 5V?   
I had expected to get closer to 0.5W!

 

We would not expect the ADL5324 to produce 0.5W, on a 3 V supply. Below is data
from characterization with the tuning recommended for 420MHz – 494MHz, using a
supply voltage of 3.3V. The tuning is the recommended tuning shown on page 17 &
18 of the ADL5324 RevB datasheet. This is the same tuning used for 5V. All
tuning of the ADL5324 was optimized for 5V performance.
After determining the 5V performance was satisfactory the part was run at
3.3V.  On a 3.3V supply I expect to see an input power of 7.9dBm for an OP1dB
of 23.64dBm.

All inductors used in the tuning of the device are coilcraft wire wound type. 
Capacitors are Murata 0402 Hi Q, GRM615 series.  So for A 3V supply, 0.25W is
what I would expect for P1 dB.


3.3 V data
======================
Freq   Gain    P1dB     OIP3_10
  
420  16.782  23.637  29.0395
457  17.202  24.219  30.0705
494  17.182  24.701  31.029

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