Takashi Suga

A gate-array-based 666 MHz VLSI test system

A 666 MHz VLSI test system with a dedicated memory test pattern generator was developed. A loose-timing data transfer scheme was employed for better integration of a shared-resource unit into the per-pin tester-architecture, Timing control resolution of 12.5 ps was achieved within a normal framework of a gate array LSI. A simple and low-cost timing calibration-technique was developed to offer accurate test timings. Parallel operation of the memory test pattern generators was used to realize a non-interrupted pattern generation at the maximum speed.

Magnetic near-field probe for GHz band and spatial resolution improvement technique

This paper reports magnetic near-field probe for high frequency band up to 10 GHz and novel measurement technique for improvement of spatial resolution. We fabricated two types of magnetic near-field probe and evaluated frequency characteristics for magnetic and electric near-field in isolation. For the measurement results, we proposed accurate equivalent circuit of probes and evaluated each value of lumped parameter to study the difference of probes. Theoretical results accorded with measurement results. With the use of a fabricated probe, a measurement technique for the improvement of spatial resolution was proposed. This technique allows improving and easy modification of spatial resolution without redesign of probe

A Study on Correlation Between the PCB Layout and EMI from Chassis

Investigations of radiated emission from a conductive chassis connected to the GND of a PCB with ICs showed higher emissions from a PCB mounted to a chassis than PCB without chassis. The results also showed that the location of the ground connection between the GND plane on the PCB and the chassis can affect emission levels by up to 9 dB. To determine the path of the noise current from the PCB to the chassis, we measured the current at their junction with a thin-current-probe. The position dependence of the junction current frequency spectra correlated with that of radiated emission spectra. Moreover, EMI levels correlated with distance from the screw to the nearest bypass-capacitor.

LSI noise model extraction with the printed reverberation board

The methodology to extract an LSI model at frequencies above 1 GHz with the printed reverberation board is presented. A test PCB has been designed and fabricated to verify the feasibility of the method. Measurement results are presented and discussed. A new random LSI model is proposed.

Influence of sympatho-adrenal system on insulin sensitivity using the euglycemic clamp technique

The aim of the present study was to further investigate the role of the adrenergic system on insulin action using the euglycemic clamp technique. Whole-body glucose metabolism (GM) was calculated as the glucose infusion rate for maintaining euglycemia under insulin infusion and used as an indicator of insulin sensitivity. Euglycemic clamps were performed in adrenodemedullated, epinephrine-treated, phentolamine-treated (alpha-blockade), propranolol-treated (beta-blockade), and epinephrine plus phentolamine and/or propranolol-treated rats. The following results were obtained at an insulin level of approximately 80 mU/l. GM in adrenodemedullated rats (13.97 +/- 0.98 mg/kg/min) was significantly higher than that of the control rats (10.26 +/- 0.50 mg/kg/min, P less than 0.01). GM in epinephrine-treated rats (1.7 mg/kg body weight/h) was 2.12 +/- 0.49 mg/kg/min (P less than 0.001 vs. control). Dose-response curves for phentolamine and propranolol established maximally effective doses (3.0 mg and 12 mg/kg body weight/h, respectively). Using these doses, GM in epinephrine plus phentolamine-treated rats (4.90 +/- 0.39 mg/kg/min) was significantly higher than that of epinephrine alone and GM in epinephrine and propranolol-treated rats (4.49 +/- 0.47 mg/kg/min) was also significantly higher than that of the epinephrine alone. GM in the epinephrine plus both propranolol and phentolamine (5.94 +/- 0.45 mg/kg/min) was significantly higher than that of the epinephrine alone, but not different from either treatment alone and was not additive. Neither phentolamine alone (9.48 +/- 1.45 mg/kg/min), propranolol alone (10.36 +/- 0.55 mg/kg/min) or the combination of blockades (11.14 +/- 0.65 mg/kg/min) had any effect on GM.(ABSTRACT TRUNCATED AT 250 WORDS)

Application of a Cavity Resonator Model for Characterization and Estimation of Radiation From a PCB–Chassis System

The electric far-field radiated from a printed circuit board (PCB)-chassis system is characterized using a cavity resonator model employing the far field calculated using an equivalent magnetic current loop. The inductive network method with measured current flowing through screws as a stimulus is used to calculate the frequency spectra of the electric field strength along the edge of the PCB with various locations of screws that connect the PCB ground to the chassis. Electric far fields from the equivalent magnetic current loop were derived using correction coefficients that incorporate the asymmetric dimensions of a parallel pair of PCB planes and the chassis. The calculation results reveal that the horizontal far field exceeds the vertical far field due to the asymmetric size coefficients and exhibit good agreement with the measurement results.

Double position-signal-difference method for electric near-field measurements

A position/signal difference method for electric near-field measurements has been investigated and extended to a double position/signal difference method in order to independently extract the normal and tangential electric near-field components using two measurements at slightly different heights above the test object. A printed monopole probe was fabricated and used for electric near-field measurements above a microstrip line using the proposed method. In addition, full-wave electromagnetic simulations were carried out and the measured normal and tangential components were found to be in good agreement with the simulation results at 1 GHz.

Overview of component level EMC characteristics for HEV application

This article presents the power point presentation on the overview of component level testing for HEV products and simulating actual vehicle condition at component-level that would be the most important. A fundamental study of the emission from HV system was calculated and characterized with consideration of effects from HV related typical parameters. The noise source and effects of low voltage system was investigated, with the necessary consideration of coupling between LV and HV system.

An investigation on the reduction technique of radiated emission from chassis with PCB

Correlation between radiated emission from chassis with PCB and the junction current which is the current flowing through screws connecting PCB GND to chassis GND was investigated, and new technique to reduce the junction current was proposed. The measurement results of the junction current frequency spectra showed strong correlation with the emission from chassis with PCB. Also investigation using meshed LCR network SPICE model of PCB and chassis was performed. The calculation results of the junction current showed good correlation with measurement results for frequency spectrum and it suggested that the closer to screw bypass capacitor is placed, the lesser current flows through junction. That new concept was validated by actual measurement and the results of radiated emission showed 19 dB improvements at 320 MHz.

Model-based analysis of screw locations to reduce radiation from a PCB-chassis structure

The effect of the location of screws that connect PCB ground with the chassis has been studied using a SPICE circuit simulation model created by the multilayered finite difference method (MFDM). The model includes the power and ground planes of the PCB and the chassis. By using the created model, the impedance between the ground of the PCB and chassis at every location and the current flowing through the screw when it is placed to connect the ground with the chassis was calculated. The investigation results suggest that the node at which the higher impedance can be observed provides a lower screw current. Furthermore, it revealed that even just two screws connecting the ground with the chassis can provide a lower current than a single screw connection. Far-field measurements were performed to validate the investigation results.