Cavity-backed slot antenna loaded with non-Foster negative inductors

We have demonstrated a high-gain, shallow-cavity, low-frequency, cavity-backed slot antenna (CBSA) by loading its cavity with an active artificial magnetic conductor (AAMC) enabled with non-Foster negative inductors. The AAMC is mounted 1.27 cm below the cavity ceiling. The non-Foster circuit (NFC) allows the AMC resonant frequency to be tuned to as low as 200 MHz with ±90° bandwidth as high as 90%. As a result, the AMC enhances the CBSA's gain by 15 dB when radiating in its fundamental mode at ~300 MHz.