Abstract: A method for fabricating semiconductor device includes forming an alternating stack that includes a lower multi-layered stack and an upper multi-layered stack by alternately stacking a dielectric layer and a sacrificial layer over a substrate, forming a vertical trench that divides the upper multi-layered stack into dummy stacks, and forming an asymmetric stepped trench that is extended downward from the vertical trench to divide the lower multi-layered stack into a pad stack and a dummy pad stack, wherein forming the asymmetric stepped trench includes forming a first stepped sidewall that is defined at an edge of the pad stack, and forming a second stepped sidewall that is defined at an edge of the dummy pad stack and occupies less area than the first stepped sidewall.

Abstract: A normalizing heat-treated steel sheet having good low-temperature impact toughness and a method for manufacturing the same is provided. The normalizing heat treated steel sheet of the present invention contains, by weight %, C: 0.04 to 0.1%, Si: 0.05 to 0.5%, Mn: 1.0 to 2.0%, Sol. Al: 0.015 to 0.04%, Nb: 0.003 to 0.03%, Ti: 0.005 to 0.02%, Cu: 0.35% or less, Ni: 0.05 to 0.8%, N: 0.002 to 0.008%, P: 0.01% or less (excluding 0%), S: 0.003% or less, and a balance of Fe and unavoidable impurities and has a steel microstructure composed of 70 to 90 area % of polygonal ferrite having a grain size of 20 ?m or less, and 10 to 30 area % of spheroidized pearlite.

Abstract: An extremely high frequency parasitic signal suppression circuit for use in a local oscillator of an extremely high frequency radio or satellite communication system to eliminate parasitic signals included in a local oscillation signal. A first direct current cut-off device consisting of a microstrip line is connected between the output terminal of a phase-locked oscillator and the input of an amplifier, and to a first low pass filter to supply a direct current source for the amplifier. A second direct current cut-off device and second low pass filter are connected to the output terminal of the amplifier in the same manner as the input terminal.

Abstract: A double band frequency converter for converting high frequency signals of the microwave radio band to a lower band for a microwave radio band frequency receiver having a wave guide and a low noise amplifier for low-noise amplifying the high frequency signals at the higher microwave frequency band supplied through the wave guide. The double band frequency converter comprises a first frequency converter for converting frequency of the output of the low-noise amplifier, a second frequency converter for frequency-converting the output of the first frequency converter, and an IF amplifier for selectively amplifying the outputs of the first frequency converter or the second frequency converter and an intermediate frequency selection circuit for selecting an output of the first frequency converter or the second frequency converter and supplying it to the IF amplifier.