The Mw 9.0 Tohoku-Oki earthquake that hit the mainland Japan on 11 th March, 2011 had resulted a devastating Tsunami due to an active thrusting between the Pacific and the North American Plates. Static and kinematic o...The Mw 9.0 Tohoku-Oki earthquake that hit the mainland Japan on 11 th March, 2011 had resulted a devastating Tsunami due to an active thrusting between the Pacific and the North American Plates. Static and kinematic offsets at the offshore epicentre of the Mw 9.0 event remain unanswered and being investigated along with their near and far field limiting distances from the epicentre. Accordingly, offset measurements from 60 continuously operating IGS and GEONET GNSS stations were radially classified from the epicentre and interpreted with analytical models to find their linear offset decay rates. Co-and post-seismic static positional anomaly offsets of sixty days show almost all near field stations had strong or appreciable eastward or south eastward static shifts. Near stations(<250 km) showed both kinematic and static offsets. GEONET station ’0175’ showed maximum resultant static offset of-4.5 m, which diminishes approximately 1-2 cm at far sites like SMST and AIRA. Characteristic decay duration(’b’) of the mean kinematic co-seismic shift(’a’)of near field stations was 17.28 s during earthquake hours with an EW component shift >1.5 m. Spatial models of projected N-S static and kinematic offsets show their asymmetrical distributions around the epicentre with maximum model offset of-1.84 m displaced towards south at-45 km north of the epicentre. The Tohoku-Oki earthquake produced a resultant kinematic offset of-10.2 m towards East at its offshore epicentre;while the estimated near field static offset is ~9.82 m. However, both estimates are bigger than double the resultant offset measured value(~4.3 m) in the Japanese mainland using GPS. The difference in the kinematic and static near field offsets highlight that the near surface had elastic or in-elastic kinematic strain dissipation as against the lithospheric level viscoelastic static response, which resulted rapid kinematic strain release(1.12 cm/km)within the limiting radius of ~220 km from the Tohoku-Oki epicentre.展开更多
Static phase offset (SPO) in conventional multiplying delay-locked loops (MDLLs) dramatically degrades the deterministic jitter performance. To overcome the issue, this paper presents a new SPO reduction technique for...Static phase offset (SPO) in conventional multiplying delay-locked loops (MDLLs) dramatically degrades the deterministic jitter performance. To overcome the issue, this paper presents a new SPO reduction technique for MDLLs. The technique is based on the observation that the SPO of MDLL is mainly caused by the non-idealities on charge pump (e.g. sink and source current mismatch), and control line (e.g. gate leakage of loop filter and voltage controlled delay line (VCDL) control circuit). With a high gain stage inserting between phase detector/phase frequency detector (PD/PFD) and charge pump, the equivalent SPO has been decreased by a factor equal to the gain of the gain stage. The effectiveness of the proposed technique is validated by a Simulink model of MDLL. The equivalent SPO is measured by the power level of reference spur.展开更多
文摘The Mw 9.0 Tohoku-Oki earthquake that hit the mainland Japan on 11 th March, 2011 had resulted a devastating Tsunami due to an active thrusting between the Pacific and the North American Plates. Static and kinematic offsets at the offshore epicentre of the Mw 9.0 event remain unanswered and being investigated along with their near and far field limiting distances from the epicentre. Accordingly, offset measurements from 60 continuously operating IGS and GEONET GNSS stations were radially classified from the epicentre and interpreted with analytical models to find their linear offset decay rates. Co-and post-seismic static positional anomaly offsets of sixty days show almost all near field stations had strong or appreciable eastward or south eastward static shifts. Near stations(<250 km) showed both kinematic and static offsets. GEONET station ’0175’ showed maximum resultant static offset of-4.5 m, which diminishes approximately 1-2 cm at far sites like SMST and AIRA. Characteristic decay duration(’b’) of the mean kinematic co-seismic shift(’a’)of near field stations was 17.28 s during earthquake hours with an EW component shift >1.5 m. Spatial models of projected N-S static and kinematic offsets show their asymmetrical distributions around the epicentre with maximum model offset of-1.84 m displaced towards south at-45 km north of the epicentre. The Tohoku-Oki earthquake produced a resultant kinematic offset of-10.2 m towards East at its offshore epicentre;while the estimated near field static offset is ~9.82 m. However, both estimates are bigger than double the resultant offset measured value(~4.3 m) in the Japanese mainland using GPS. The difference in the kinematic and static near field offsets highlight that the near surface had elastic or in-elastic kinematic strain dissipation as against the lithospheric level viscoelastic static response, which resulted rapid kinematic strain release(1.12 cm/km)within the limiting radius of ~220 km from the Tohoku-Oki epicentre.
文摘Static phase offset (SPO) in conventional multiplying delay-locked loops (MDLLs) dramatically degrades the deterministic jitter performance. To overcome the issue, this paper presents a new SPO reduction technique for MDLLs. The technique is based on the observation that the SPO of MDLL is mainly caused by the non-idealities on charge pump (e.g. sink and source current mismatch), and control line (e.g. gate leakage of loop filter and voltage controlled delay line (VCDL) control circuit). With a high gain stage inserting between phase detector/phase frequency detector (PD/PFD) and charge pump, the equivalent SPO has been decreased by a factor equal to the gain of the gain stage. The effectiveness of the proposed technique is validated by a Simulink model of MDLL. The equivalent SPO is measured by the power level of reference spur.
