Abstract: A transmission circuit includes a first-stage circuit, a second-stage circuit, a negative active feedback circuit and a current buffer. The first-stage circuit includes at least an active MOS device for receiving an input voltage and issuing a first voltage signal. The active MOS device has an inductive feature during operation in a high frequency mode to compensate the first voltage signal. In response to the first voltage signal, the second-stage circuit outputs a first output voltage. The negative active feedback circuit may enhance the bandwidth of the first output voltage. The current buffer may enhance the gain value of the first output voltage. A second voltage signal is issued from the first-stage circuit and compensated by the first output voltage transmitted from the current buffer to enhance the bandwidth and the gain value thereof. In response to the compensated second voltage signal, the second-stage circuit outputs a second output voltage.

Abstract: A method for making negative thermal expansion material zirconium tungstate (ZrW2O8) comprise: (a)forming a gel wrapped solid product comprising a water-soluble zirconium compound, preferably zirconium oxyhalides or zirconium oxynitrates and a water-insoluble tungsten compound, preferably tungsten powder or tungsten oxide powder; and (b)heating the gel wrapped solid product to a temperature sufficient to form ZrW2O8; the temperature required for forming zirconium tungstate should be at least about 1165° C.; the upper limit of the temperature should be about 1250° C., and preferably should be about 1180˜1200° C.; and the time needed for the formation of zirconium tungstate is less than about 5 hours; this method has the advantages on enhancing the selectivity of the reactants, simplifying production process, reducing the cost of reagent, and facilitating the mass production for making ZrW2O8.