UHF Electrically Small Box Cage Loop Antenna With an Embedded Non-Foster Load

Traditional impedance-matching methods typically employ matching networks at the antenna input terminals. Alternatively, the antenna may be embedded with a non-Foster load to enhance the radiation bandwidth. This method is demonstrated here with the design of an electrically small box cage loop antenna (ka ~ 0.37). Simulated results using ideal non-Foster components are compared against a negative impedance converter (NIC) circuit realization. These results show that the VSWR bandwidth is improved 8 × by using the NIC circuit. Simulated radiation efficiencies are also presented for the first time.