A NOVEL DESIGN OF 0.8 GHz-1.2 GHz NEGATIVE IMPEDANCE SERIES CAPACITOR CIRCUIT

摘要

Negative impedance converter (NIC) is a broadband matching technique in radio frequency (RF) based on the non-Foster theory. This technique in conjunction with the effect of negative impedance has been proven to achieve a wider impedance matching bandwidth than other techniques. However, it still has problems in the areas of flexible connectivity, and mismatch in the real part of negative impedance and power consumption. Those problems have led to non-Foster circuits (NFC) not being trusted as much as high unload Q module for broadband matching. In this paper, we propose a new idea for NFC that uses balun transformers to achieve negative reactance in 0.8 GHz to 1.2 GHz with the real part of the impedance is matched to 50 Omega when the imaginary part (normally, it is the reactance of negative impedance circuit) does not change. Finally, we show and compare our results with the ideal impedance of negative lump components in both the Smith Chart and reactance. (C) 2016 Wiley Periodicals, Inc.