A 0.15 um Depletion Mode GaN Bootstrapped N-path Filter with 23dBm Inband Blocker Handling

This paper suggests linearity improvement of N-path filters, using a Depletion mode (D-mode) 0.15um GaN process. GaN has a high breakdown voltage which can support large powers. By simulating one port 4-path filter with 1 GHz LO frequency and 1.001 GHz RF input frequency (1MHz baseband), integrated with BB node bootstrap circuit based on LO and BB combination, we demonstrate a high-Q filter with 14MHz bandwidth and 14dB rejection ratio for the inband (IB) blocker of 23dBm. We also show a high linearity performance by achieving IB P1dB of 26dBm, which is 14dB higher than the same N-path without bootstrap.