An electronically tuneable inductance with extended frequency range
The extension of the usable frequency range of an electronically tuneable inductance circuit is investigated. By means of numerical and analytical studies, the transistor-internal reverse transfer capacitance can be identified as a frequency-limiting element, which must be minimised. This is achieved by circuitry-wise compensation of the capacitive effect by introducing an additional inductance. The concept is verified through measurements of the practical implementation and shows an extension of the frequency range by two octaves throughout the VHF range, which proves beneficial for applications such as broadband matched and tuneable transmission lines, amplifier circuits, oscillators, or filters.
Experimental proof-of-principle of a passive, nearly reciprocal, transistor-based tuneable RF inductance
An innovative approach for tuneable reactances using the example of electronic inductances is introduced and the operation principle affirmed by measurement. Hitherto solutions for variable inductances often lack applicability in serial paths or do not exhibit passive behaviour. The presented circuit shows, even though transistor-based, a passive and reciprocal tuneable inductive behaviour at its terminals over a broad range of biasing conditions and frequencies. Thereby it accommodates more degrees-of-freedom in circuit design and possibilities for interesting applications, e.g., in integrated circuit design for a multitude of relevant applications in sensing and mobile communications. A test board was implemented and measured, confirming the principle-of-operation in agreement with numerical simulations, demonstrating a transistor-based, passive, tuneable, nearly reciprocal inductance over a frequency range larger than a decade.
Research on automatic tracking solar power system
The paper elaborates the features of solar power. On the foundation of it, it analyses the composing, the theory and the features of solar power system of automatic tracking, analyzing the function of mental composing and the important technology, making a compartment of the amount of generation of solar power system of automatic tracking and that of common solar power system.