1-2hit |
Tsuyoshi YAKIHARA Katsuyoshi HAMASAKI Tsutomu YAMASHITA Toshiaki MATSUI Risao HAYASHI
All-NbN edge junction nanobridges have been reproducibly fabricated. They had nearly ideal characteristics: sharply defined critical current, high resistance100Ω, sharp gap structure at about 4 mV, large IoRn products, and low excess current. The sharp LC resonance step at about 1.5 mV was observed in the nanobridge SQUID's. The noise equivalent power was NEP10-19 W/Hz in Josephson mixing at 101 GHz.
Haruo KOBAYASHI Toshiya MIZUTA Kenji UCHIDA Hiroyuki MATSUURA Akira MIURA Tsuyoshi YAKIHARA Sadaharu OKA Daisuke MURATA
This paper describes the design and performance of a high-speed 6-bit ADC using SiGe HBT for measuring-instrument applications. We show that the Gummel-Poon model suffices for SiGe HBT modeling and then we describe that the folding/interpolation architecture as well as simple, differential circuit design are suitable for ADC design with SiGe HBT. Measured results show that the nonlinearity of the ADC is within 1/2 LSB, and the effective bits are 5. 2 bits at an input frequency of 100 MHz and 4. 2 bits at 200 MHz with 768 MS/s. We also describe some design issues for folding/interpolation ADC.