Demonstration of High-Voltage 4H-SiC Bipolar RF Power Limiter

We present the design and fabrication of the first high-voltage 4H-SiC RF power limiter. First, Schottky and PiN diodes are compared for power limiter applications by numerical simulations. Small-signal S-parameters and large-signal operation are then simulated based on our device design. The fabrication is based on a SiC PiN diode with at least 900V blocking capability and packaged into a 50 microstrip transmission line fixture. Small signal insertion and return losses are measured in the frequency band from 100MHz to 3GHz after packaging and agree well with our simulation. The limiter has an insertion loss of only 0.6dB at 1GHz. This is believed to be the first 4H-SiC high-voltage RF power limiter, as well as one of the best SiC limiters in terms of low small-signal transmission loss up to gigahertz frequencies.