A high gain, compact active disc-cone antenna based on non-foster matching circuit

The conventional passive matching technology of antenna is limited by the gain-bandwidth constraints. The antenna miniaturization can be only achieved in a very narrow frequency band with a low gain in the high frequency (HF) and very high frequency (VHF) bands. In order to realize the broadband matching and high gain design of the miniaturized disc-cone antenna, a non-Foster matching circuit, which consists of a negative impedance converter, a transformer and a current buffer, is proposed for impedance matching of the miniaturized disc-cone antenna. It is different from the conventional non-Foster matching circuit, which is merely composed of a negative impedance converter. Compared with the classical design, the size of the miniaturized antenna loaded with the proposed circuit is reduced by 60.9%. The S₁₁ parameter of the antenna is less than −15 dB in the frequency range of 150–250 MHz, and the gain improvement of the non-Foster matching circuit to the miniaturized disc-cone antenna is more than 10 dB. Therefore, the matching circuit proposed in this research has better impedance matching performance and gain improvement compared to the conventional design. The results from the experiments validate the feasibility and effectiveness of the new design scheme.