Automatic LC network tuner based on negative resistances

• Published in: Electronics letters Vol. 51; no. 1; pp. 25 - 27
• Main Authors: Silva, P.M, Rottava, R, de Sousa, F.R
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 08.01.2015
• Subjects: automatic LC network tuner; circuit complexity; circuit tuning; Circuits and systems; Constants; Electric potential; inductor‐capacitor network; input signals; LC circuit; LC circuits; low complexity algorithms; negative resistances; negative resistor; Networks; production line testing; Quality factor; Q‐factor; radiofrequency identification tags; Receiving; receiving signal frequency; Resistors; Tuners; Voltage; voltage detector decision range; Q-factor; circuit complexity; low complexity algorithms; input signals; voltage detector decision range; negative resistor; LC circuit; inductor-capacitor network; quality factor; production line testing; negative resistances; LC circuits; automatic LC network tuner; circuit tuning; radiofrequency identification tags; receiving signal frequency
• ISSN: 0013-5194; 1350-911X; 1350-911X
• DOI: 10.1049/el.2014.3800

A novel technique to tune an inductor–capacitor (LC) network based on a receiving signal frequency is proposed. The method consists of using a negative resistor to artificially increase the quality factor of the LC circuit to reduce the decision range of the voltage detector. This approach allows the use of low complexity algorithms that converge in a few steps. The technique was validated through a demonstrator for radiofrequency identification tags in production line testing, with satisfactory results. The designed negative resistor maintained a constant resistance for a large range of input signals.