To measure the performance of devices in non-linear regimes, the platform has developed non-linear "Load-Pull" benches and has an infrared microscope.
Non-linear 50GHz
To characterise the power performance of microwave devices, the centre has a non-linear vector network analyser operating up to 50GHz (Keysight N5245A). This system can be used to determine the Gp (power gain), Pout (power available at output) and Pae (power added efficiency) of transistors and amplifiers.
As these parameters can only be determined in saturated mode, a high level of power is required to excite the device under test. Several amplifiers are available for this purpose, 2 amplifiers delivering 10W from 6 to 18GHz, 2 amplifiers delivering 2 and 5W from 40 to 44GHz and an amplifier delivering 12W between 39 and 40GHz.
These measurements can be made in 'load-pull' mode by modifying the impedance presented at the output of the device under test, using two possible techniques: passive load-pull (tuner) or active load-pull (active load). This makes it possible to determine the optimum impedance for maximising Gp, Pout or Pae.
All these measurements are possible in CW (continuous) or pulse (pulsed bias + pulse RF) mode, with a pulse width of 1µs and a duty cycle of 1%. Pulse measurements eliminate trapping and thermal phenomena, maximising the performance of the components under test.
Non-linear 94GHz
The characterisation centre also has a power characterisation system operating at 94GHz. Like the NVNA, this system enables power characterisation of microwave devices such as transistors and amplifiers. It has two power amplifiers operating at 94GHz and delivering +20dBm and +30dBm to excite the device under test, as well as an impedance tuner for carrying out these measurements in load-pull mode.
Contact: Etienne OKADA etienne.okada@univ-lille.fr 03 20 19 79 30
