PP 2N5109 RF Amplifier

OIP3 Measurements vs. Pin

As in schematic below with 1kΩ feedback 2.7kΩ bias resistor modified for 40mA per 2N5109 Emitter current Rigol DG1032Z Output = 4.97MHz and 5.03MHz LPF Rigol DG1032Z Output = 8.03MHz and 12MHz 3dB Coupler VNWA in Spectrum Analyzer mode Three configurations: DG1032Z -> Coupler -> DUT > -40dB -> VNWA Port 2 DG1032Z -> Coupler -> -20dB -> DUT > -40dB -> VNWA Port 2 DG1032Z -> Coupler -> -4dB -> DUT > -20dB -> LPF -> VNWA Port 2 Theoretical OIP3 = 20*log10(((40/1414)**2)*200000) = 44.1dBm

OIP2 Measurements vs. Pin

As in schematic below with 1kΩ feedback 2.7kΩ bias resistor modified for 40mA per 2N5109 Emitter current Rigol DG1032Z Output = 5.03MHz and 10MHz 3dB Coupler VNWA in Spectrum Analyzer mode

Emitter to Base Transformer Feedback

Feedback transformers = FT37-43 7T:1T Transformer phasing details Gain = 20dB OIP3 = 32dBm NF = 2.6dB

Collector to Base Resistor Feedback