Abstract: A two-port dual-gate field-effect transistor for amplifier applications, wherein a self-bias circuit includes a number of passive elements, such as resistors, diodes and capacitors, is utilized to coupled the output of the amplifier with a second gate of the dual-gate device as a bias source, which transforms the conventional three-port cascade topology into a two-port dual-gate device so as to facilitate device testing, modeling, and packaging for discrete device application. The technology improves the RF performance in conventional two-port single-gate HEMT devices, with slight noise figure degradation.

Abstract: A two-port dual-gate field-effect transistor for amplifier applications, wherein a self-bias circuit comprising a number of passive elements, such as resistors, diodes and capacitors, is utilized to coupled the output of the amplifier with a second gate of the dual-gate device as a bias source, which transforms the conventional three-port cascode topology into a two-port dual-gate device so as to facilitate device testing, modeling, and packaging for discrete device application. The technology is for improving the RF performance of conventional two-port single-gate HEMT device, with slightly noise figure degradation. This innovation doesn't require complicated RF testing and modeling as compared with conventional dual-gate devices. The two-port dual-gate device fits packaging molds of conventional two-port discrete device, hence the production line thereof can be easily extended to low noise amplifier and power amplifier applications.

Abstract: A method for preparing a magnetic recording medium includes the following steps of providing a substrate; providing a solution consisting essentially of ions of cobalt, manganese and iron in deionized water; and preheating the substrate and spraying the solution onto the preheated substrate at an elevated temperature to uniformly distribute droplets thereon and form a magnetic recording medium film on the subtrate. Such method can prepare a magnetic thin film which has a high recording density and is cost-effective.

Abstract: A method for preparing a magnetic recording medium includes the steps of providing a substrate, providing an alloy composite target attaching thereon Co and Fe pellets to modify the composition of this magnetic recording medium, and utilizing the target to form a (Co,Mn) modified .gamma.-Fe.sub.2 O.sub.3 thin film on the substrate under controlled conditions. Such method can provide a magnetic recording medium which is cost-effective and has a better SNR, a better resistance to corrosion and a high coercivity.