A true enhancement-mode junction pseudomorphic HEMT (JPHEMT) with a high threshold voltage (V/sub th/) Of +0.5 V was developed for single-supply power amplifiers. The novel JPHEMT exhibits an extremely low standby leakage current. The leakage current at 25/spl deg/C is 2.2/spl times/10/sup -10/ A/mm and even at 85/spl deg/C is 8.6/spl times/10/sup -9/ A/mm.… (More)
A detailed experimental study is presented of a 1 MW, 170 GHz gyrotron oscillator whose design is consistent with the ECH requirements of the International Thermonuclear Experimental Reactor (ITER) for bulk heating and current drive. This work is the first to demonstrate that megawatt power level at 170 GHz can be achieved in a gyrotron with high efficiency… (More)
For 10-Gbps optical transmitter, we have developed a low-power consumption electroabsorption modulator driver IC and observed good characteristics. The power consumption was 0.85 W at a supply voltage of -5 V under the 2.5 Vpp output condition.
Effective reflectivity of fiber Bragg grating (FBG)-locked 980-nm laser module was analyzed relating to spatial hole burning. The optimized external-cavity design realized wavelength fluctuation under /spl plusmn/0.3 nm. Power degradation by FBG was below 10%. End-of-life guaranteed power exceeded 150 mW@250 mA/spl sim/300 mA.