YO4HFU
PGA-103+ Preamplifier

 

 

PGA103+ is a MMIC GaAs PHEMT with good performances for VHF-UHF. Broadband, high IP3 point, low noise and high gain, make a good choise for terrestrial LNA, transverters frontend or measurement instruments.
At 144MHz: NF~0.55dB, Gain=24.2dB and IIP3=9,5dBm (2 tones, 200KHz spaced). Drain current: 90-100mA/5V (high IP3 requirement).
At 432MHz: NF~0.85dB, Gain=20dB
At 70MHz:
NF~0.3dB, Gain=23.5dB
At 50MHz:
NF~0.35dB, Gain:=22.5dB

Noise/Gain measurements done using Eaton 2075 and RFD2305 (5dB ENR) Noise Source.





The preamplifier is stable but is extremely sensitive for ESD. I managed to destroy several pieces. This happen during connection/disconnection of the input. When the current starts to increase above 100mA, PGA103 is already destroyed...
I recommend to protect the input using a BAV99 schottky diode and 1M resistors, connected between input and ground. No any fault device after modification.




PCB Sprint Layout and pdf
PGA103+ Schematic



 

 

 

 

 


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