Osamu Toyoda

55.1: Invited Paper: High-Luminance and Highly Luminous-Efficient AC-PDP with DelTA Cell Structure

To improve the performance of PDPs, we developed an AC-PDP with the Delta Tri-color Arrangement (DelTA) cell structure and arc-shaped electrodes. The experimental panel has a pixel pitch of 1.08 mm and luminous efficiency of 3 lm/W at a luminance of 200 cd/m2. Moreover, its peak luminance can be greater than 1000cd/m2.

MEMS tunable bandpass filters on high-k LTCC

This paper describes a novel MEMS tunable bandpass filter, which operates at the Ku band and features an extremely low insertion loss of −1.23–2 dB, a small size of 3.3 mm by 1.7 mm and a wide continuous tuning range of 36%. The tunable filter is based on MEMS-varactors-loaded microstrip resonators and has been directly constructed on a high-k low-temperature-co-fired-ceramics (LTCC) wiring wafer using newly developed MEMS-on-LTCC technology, which allows use of high-k materials as the filter substrate enabling a small size and low insertion loss, and greatly simplifies the fabrication and packaging processes. MEMS-on-LTCC technology combines the advantages of LTCC and MEMS and is promising for future reconfigurable radio front-end modules.

High‐luminance and highly luminous‐efficient AC‐PDP with DelTA cell structure

To improve PDP performance, we developed an AC-PDP with the Delta Tri-Color Arrangement (DelTA) cell structure and arc-shaped electrodes. The experimental panel has a pixel pitch of 1.08 mm and luminous efficacy of 3 lm/W at a luminance of 200 cd/m 2 despite its conventional gas mixture of Ne and Xe (4%) and conventional phosphor set. Moreover, its peak luminance can be greater than 1000 cd/m 2 . The strong dependence of luminous efficacy on the sustain voltage is also discussed in this paper.

Miniaturized microwave tunable bandpass filters on high-k LTCC with integrated resistive vias as bias-T

This paper describes a MEMS tunable bandpass filter operating in the S band region and featuring a low insertion loss of −2.3 dB and small size of 3.7 mm by 4.1 mm. The tunable filter is based on MEMS-varactors-loaded microstrip resonators and has been directly constructed on a high-k low-temperature-co-fired-ceramics (LTCC) wiring wafer whose dielectric constant is 50, using MEMS-on-LTCC technology. The RF signal paths are isolated from the MEMS driving paths by built-in high-resistivity-vias, leading to low insertion loss. RF power-proof performance was evaluated by applying OFDM signals to the device. The results confirm that MEMS tunable filters are sufficiently linear at cell phone power level.

29.1: Low Cost Barrier Rib Formation Technologies for High Efficiency PDPs

Two new techniques of barrier rib formation applicable to a variety of structures for high-performance PDPs suitable for mass-production were developed. The two techniques are mold replication, using adhesives with a reusable mold, and direct glass sculpting. Both equipment investment and material costs were reduced from previous methods in each technique. The feasibility of each method was demonstrated by fabrication tests and measured performance of test panels.

A wireless motor-condition, precise analysis system using a highly efficient vibration-energy harvester

A wireless motor condition precise analysis system that uses a highly efficient energy harvester is described in this paper. A continuation data sampling is required for the condition analysis of a motor. We developed the technology that makes a vibration energy harvester highly efficient and reduces the energy consumption of the whole system. A battery-less wireless analysis system was created in which the operation and life prediction of a motor was made possible. The original structure of the highly efficient energy harvester was developed using magnetic strain material rods. Electric power is generated using the coils around the rods when the rods are bent by external vibration. Therefore, the efficiency of the energy harvester is raised by optimizing the internal stress of the rods using buffer plates. The energy harvester has a resonant frequency of 90 Hz, a maximum electromotive force of 2.7 V, and a maximum power of 28 mW using 0.5-G acceleration. The wireless motor condition monitoring system includes the energy harvester, an end device, a coordinator, and a PC for data processing. The end device for the monitoring and data transfer is operated using only the electric power from the energy harvester. The monitoring information on the temperature, humidity, supplied voltage, and communication quality every three seconds and for the vibration waveform every five seconds is transmitted to the coordinators by the end device and handled by the PC. This enables for the condition monitoring and fault prediction of the motor.

A highly reliable single-crystal silicon RF-MEMS switch using Au sub-micron particles for wafer level LTCC cap packaging

This paper presents a small packaged, reliable and low-voltage driven RF-MEMS switch for wireless communication. We developed novel fabrication process of an RF-MEMS switch using a PZT actuator without a backside cavity to realize wafer-level-packaging (WLP). We also developed organic-free WLP process using sub-micron Au particles simultaneously to contact electrically and to seal hermetically with a low temperature co-fired ceramics (LTCC) wafer as a cap on a multilevel height RF switch. As a result, we obtained a small packaged SPST switch, which is in the small size of 1.4 × 0.9 × 0.8 mm. The RF-MEMS switch operated keeping a low contact resistance (<;3 Ω) up to 1 billion cycles at a low-power condition (DC 1 mW).

A 3D heterogeneous integration method using LTCC wafer for RF applications

This paper describes the concept, fabrication process technologies and performance of a novel 3D heterogeneous integration method developed for RF applications. This method combines the advantages of LTCC, passive integration and MEMS technologies and is promising for the miniaturization and multifunction of future RF-modules. The basic concept is to form a large-size LTCC wiring wafer, and then to form high-Q passives or MEMS directly on the wafer surface. Other functional devices such as the ICs, SAWs are mounted above the surface-formed devices. LTCC wafer can provide dense interconnects and backside pads to provide input and output paths. All of the fabrication processes are carried out at wafer level, which leads to high productivity. A miniaturized duplexer and a MEMS tunable filter were constructed to demonstrate its feasibility and effectiveness.

A sticking-free and high-quality factor MEMS variable capacitor with metal-insulator-metal dots as dielectric layer

This paper describes a novel design of a MEMS variable capacitor with high operating reliability and high quality factor. Metal-Insulator-Metal (MIM) dots between a fixed electrode and a movable electrode in a variable capacitor is proposed. A Fabricated MEMS capacitor was operated one billion or more times without sticking. It demonstrated a high quality factor of 200 at 0.5 pF. It was experimentally confirmed that MIM dots effectively achieve a sticking-free and high-quality-factor MEMS variable capacitor.

Piezoelectric reliable RF-MEMS switch with narrow contact-gap using wafer-bond packaging

This paper presents a low-cost packaged and reliable piezoelectric-actuated RF-MEMS switch for mobile communications. We fabricated a stiff single crystal silicon (SCS) beam that has an actuator and a contact bump on an SOI wafer without backside etching. We bonded the wafer to a ceramic cap wafer, directly packaging a switch with a contact gap of 0.5-μm not using sacrificial layers. The switch operated up to 1 billion cycles keeping a low insertion loss (<;0.4 dB up to 5GHz) at 20-V driving voltage. The surface mountable SPST switch was 1.6 × 1.1 × 0.8 mm in size.