Tsuneo Tsukagoshi

Challenging EMC problems on two-dimensional communication systems

While “Two-dimensional communication” (2DC) is expected as a new sensor network technology, there are concerns of electromagnetic compatibility (EMC) issues. Although the transmission mode along the 2DC sheet has an evanescent property normal to the sheet surface, several discontinuous parts along the sheet can produce the radiation modes, which are emitted to surrounding environment resulting in electromagnetic interference (EMI) problems. This paper describes a preliminary investigation of radiation from a 2DC system. In particular, the radiation mechanisms from the discontinuous parts of a coupler-sheet system are explained using the plane wave theory of electromagnetics and verified by numerical simulations. Furthermore, promising countermeasures are proposed to reduce the radiated emissions from two main discontinuous parts of the system: the sheet edges and the coupler-covered regions. The proposed countermeasures are shown to be effective by analyzing elementary configurations.

Highly-reliable semi-autonomous vehicle control on lattice lane

The vehicle curve movement reliability has been improved by a variable curve movement radius control technique involving a curve angle monitoring method and a nonlinear fuzzy control technique. In consequence, the successful rate achieved for an obstacle avoidance movement has risen from 96% in conventional curve movement technique up to 98%.<<ETX>>

LSI immunity test method by direct GND pin injection

This paper proposed a method to test the immunity of LSIs where RF noise is injected into the GND pin of an LSI. We concluded that the GND pin injection test we propose is more suitable for evaluating actual LSI immunity against RF noise than the VDD pin injection test based on conventional Direct RF Power Injection (DPI).

The influence of the instruction codes on radiated near-magnetic-fields

It has been said that the radiated electromagnetic emission (EMI) spectra from the computer change with the kind of the program executed on the computer. In this study, as a first step to investigate the influence of program on EM, the influence of instruction codes executed on a CPU on radiated near-magnetic-field is clarified by experiments and investigation on the timing chart of a CPU. It is concluded that the frequencies having peaks of near-magnetic-field spectra are observed on every frequency obtained by dividing the clock frequency by the number of clocks required for one instruction execution.

a case study on A5000

The paper describes the application of a specially designed wedge shape to improvements in the efficiency of microwave heat treatment of waste materials. The use of the absorber design technique by which wave energy is absorbed into the materials increases the efficiency, allowing them to be heated rapidly.

Study on microwave energy absorption in wedge type electromagnetic wave absorber and its application to microwave heating

In a sheet design of the two-dimensional communication (2DC) system, it is desirable to add shielding metal walls to the edges of the sheet in order to suppress electromagnetic (EM) radiation. Then, the sheet medium has the cutoff frequency similar to a rectangular waveguide, which can be determined from the width of the sheet. If the carrier frequency is less than the cutoff frequency, the power cannot be transmitted through the sheet. This paper proposes a new narrow 2DC sheet with the cutoff frequency lower than a conventional 2DC sheet with metal walls. Actually, the lower cutoff frequency can be obtained by forming a special metal pattern near the shielded walls. This can make the sheet width wider equivalently (electrical length longer). Then EM wave can propagate through a narrower sheet. Measurements using fabricated prototypes clearly show the advantage of the proposed structure.

Narrow sheet design with shielding metal walls of two-dimensional communication

We have developed miniaturized electromagnetic bandgap (EBG) structures on Si having a stopband that covers the 2.4 GHz band. By combining thin film dielectrics with inductance-enhanced EBG structures, the unit cell size can be reduced to 1 mm × 1 mm or less. Like the EBG structures embedded in conventional printed circuit boards, the stopbands can be designed using the transmission-line theory. The developed EBG structures can be integrated into Si interposers to suppress power noise.

Miniaturization of Electromagnetic Bandgap Structures with Thin Film Dielectrics for Si Interposer Applications

This paper clarifies the differential mode pulse propagation characteristics on the parallel plates consisting of DC power supply plane and its return plane, from the viewpoint of series resonance of parallel plates, experimentally and by PSPICE simulation. It is concluded that the practical pulse propagation characteristics are dominated by the characteristics of not only the parallel plates but also the wirings connected to the parallel plates

A Study on Pulse Propagation on Double Side PCB

Flip-flops were originally designed to be symmetrical for set/reset operation. This paper proposes an asymmetrical noise immunity flip-flop that has a different noise voltage for Q: HL than for Q: LH when the flip-flop malfunctions due to noise on the dc power supply. It is shown that an asymmetrical noise immunity flip-flop can be created by giving different overdrive factors (ODFs) to each of the two transistors in the flip-flop, where ODF is Ib/Ibmin (Ib: base current of initially saturated transistor, Ibmin: minimum base current required to maintain saturation).

A study on design of a flip-flop with asymmetrical noise immunity

In order to attain safety in the case of digital system upset due to noise, a device to detect the digital systems malfunction due to noise is demanded. This paper describes the design method of a noise sensor flip-flop with asymmetrical noise immunity characteristics. These characteristics mean that noise immunity of Q:H/spl rarr/L due to noise is different from that of Q:L/spl rarr/H due to noise. It is shown that this function is realized by using that the overriding factor of one transistor of output Q being different from another.