Simultaneous measurement of optical and RF behavior under CW and pulsed fully active harmonic load-pull

Here we present a system capable of simultaneous measurements of the RF and optical behavior of on-wafer devices, permitting the complete range of Fully Active Harmonic Load-Pull techniques to be employed while either observing optical phenomena such as Electroluminescence, or applying optical stimuli for trapping investigations. Full access to the backside of the wafer is achieved, allowing measurements on devices with source coupled field plates or air bridges, which normally obscure the gate region. Electroluminescence can be observed with an ultra-low light camera or a spectrometer. The test device was a GaN on silicon carbide HFET.