Abstract: Provided are a fluid agitation apparatus using a structure which is simple in shape and short in a fluid passage direction without a movable part so as to produce a sufficient effect from the viewpoint of reducing temperature fluctuation, and a thermostatic apparatus using the fluid agitation apparatus. The fluid agitation apparatus is installed in a fluid passage and includes, in an order from an upstream side thereof: a dividing part for dividing a flow of a fluid into a plurality of flows; a circumvolving part for circumvolving the fluid about an axis in a flow direction of the fluid; and an accelerating part for increasing a flow rate of the fluid.

Abstract: An active inductor having a greater inductance, low loss, and which is small is provided by the present invention. The active inductor comprises a common source FET and a cascode-connected common gate FET connected thereto for providing unidirectional feedback. The drain electrode of the front FET and the source electrode of the rear FET, consisting of the common gate cascode FET, are connected together. A resistor is connected at one end to this connection. The two terminals of the active inductor correspond to the other end of the resistor and the source electrode of the common source FET. A frequency independent negative resistance is generated in series with the inductance by this configuration. By properly tuning the resistance of the resistor, it is possible to make the impedance viewed from the two terminals to have inductance component only, and therefore an active inductor having less resistance loss is obtained.