This paper proposes a dual-polarized metasurface that utilizes multi-layer ceramic capacitors (MLCCs) for radar cross-section (RCS) reduction in the 28GHz band of the quasi-millimeter band. MLCCs are very small in size; therefore, miniaturization of the unit cell structure of the metamaterial can be expected, and the MLCCs can be periodically loaded onto a narrow object. First, the MLCC structure was modeled as a basic structure, and the effective permeability of the MLCC was determined to investigate the influence of the arrangement direction on MLCC interaction. Next, the unit cell structure of the dual-polarized metasurface was designed for an MLCC set on a dielectric substrate. By analyzing the infinite periodic structure and finite structure, the monostatic reduction characteristics, oblique incidence characteristics, and dual-polarization characteristics of the proposed metasurface were evaluated. In the case of the MLCCs arranged in the same direction, the monostatic RCS reduction was approximately 30dB at 29.8GHz, and decreased when the MLCCs were arranged in a checkerboard pattern. The monostatic RCS reductions for the 5 × 5, 10 × 10, and 20 × 20 divisions were roughly the same, i.e., 10.8, 9.9, and 10.3dB, respectively. Additionally, to validate the simulated results, the proposed dual-polarized metasurface was fabricated and measured. The measured results were found to approximately agree with the simulated results, confirming that the RCS can be reduced for dual-polarization operation.

We proposed and analyzed a fiber-reinforced ceramic (FRC) composite for a protection layer on top of an antenna mounted on the outer surface of aircraft. The manufactured FRC is a single-layered flat construct. To analyze the performance of the FRC, we extracted the material constant using the transmission/reflection (T/R) method. We described the relation between the pressure and strength of the FRC radome with respect to mechanical properties and analyzed the insertion loss with respect to electrical properties. We evaluated the characteristics of the FRC radome in conjunction with the horn antenna and showed that the analytic results for the FRC radome agree with the experiment results.

A new kind of 3D power divider based on a half-mode substrate integrated circular cavity (HSICC) is proposed. This novel power divider can reduce the size of a power divider based on normal substrate integrated circular cavity (SICC) by nearly a half. To verify the validity of the design method, a two-way X-band HSICC power divider using low temperature co-fired ceramic (LTCC) technology is designed, fabricated and measured.

A physics-based equivalent circuit model of the ceramic capacitor is proposed, which can reproduce frequency characteristics of its impedance including the often observed yet hitherto physically unexplained kinks appearing above the primary series resonance frequency. The model can also account for parasitic effects of external inductances. In order to efficiently analyze and gain engineering insight into ceramic capacitors with a large number of metallic laminae, a two-dimensional method of moments is developed that treats the laminar structure as a uniform, effective medium. It turns out that the primary resonance and the kinks can be well understood and modeled by a lossy transmission line stub with a drastic wavelength reduction. The capacitor model is completed by adding components describing the skin effect and external inductances. The modeled impedance stays within a 4% margin of error up to 5 GHz. The proposed model could greatly improve the accuracy of power distribution network simulation.

Electrical modeling for surface-mount passive components is proposed. In order to accurately capture parasitic inductance, the proposed 2-port model accounts for surrounding ground layer configurations of the print circuit board (PCB) on which the component is mounted. Our model retains conventional modeling paradigm in which component suppliers provide their customers with simulation models characterized independently of the customers' PCB. We also present necessary corrections that compensate magnetic coupling between the separated models. Impedance and its anti-resonant frequency of two power distribution networks are experimentally analyzed being non-separated modeling as the reference. The proposed model achieved very good match with the reference result reducing 7-34% error of the conventional model to about 2%.

In this study, the microwave dielectric properties of the Mg4Ta2O9 and Mg5Ta4O15 ceramics with composition ratio and sintering temperature were investigated and the dielectric resonators with these ceramics were simulated. TiO2 was doped in the Mg4Ta2O9 ceramics for improvement of temperature property. The (1-x)Mg4Ta2O9-xTiO2 and Mg5Ta4O15 ceramics were prepared by solid-state reaction method. According to the X-ray diffraction data, the (1-x)Mg4Ta2O9-xTiO2 ceramics had main phase of the Mg4Ta2O9 and MgTi2O5 peaks were appeared by additions of TiO2. In the Mg5Ta4O15 ceramics, the Mg4Ta2O9 and MgTa2O6 phase were coexisted and Mg5Ta4O15 phase was appeared with increments of sintering temperature. Microwave dielectric properties of (1-x)Mg4Ta2O9-xTiO2 ceramics were affected by MgTi2O5 and TiO2 phase. The quality factor had a little decrement compared to pure Mg4Ta2O9, but there was excellent improvement in TCRF by addition of TiO2. Densifications of the Mg4Ta2O9 and MgTa2O6 and existence of the Mg5Ta4O15 phase had influence on the microwave dielectric properties of the Mg5Ta4O15 ceramics. Dielectric constant, quality factor and TCRF of the (1-x)Mg4Ta2O9-xTiO2 and Mg5Ta4O15 ceramics sintered at 1450 were 11.5622.5, 24980186410 GHz, -36.02+19.72 ppm/ and 8.2, 89473 GHz, -10.91 ppm/, respectively. ADS was used for simulation of DR. The simulated DR with the 0.5Mg4Ta2O9-0.5TiO2 and Mg5Ta4O15 ceramics had the S21 of -35.034 dB at 11.97 GHz and -28.493 dB at 10.50 GHz, respectively.

This paper proposes a novel fiber endface preparation tool for optical fiber joints that employs thermal surface cleaning and thermal endface cutting. This tool has great advantages in terms of fiber endface preparation time, and fiber endface stability when fiber is cut repeatedly. Stable thermal surface cleaning and thermal endface cutting are achieved by selecting suitable heating conditions. The fiber endface preparation time can be reduced to 50% of that required with conventional tools. The fiber endface stability obtained using thermal cutting is more than five times better than that obtained with the conventional tool using a blade.

For V-band applications, this paper presents a fully embedded multi-layer dielectric waveguide filter (DWGF) with very low insertion loss and small size, which does not need any more assemblies such as flip-chip bonding and bond wires. The top and bottom plane are grounded, and therefore, although we make a metal housing, there will be no resonance occurrences. Especially, the proposed structure is very suitable for MMICs interconnection because the in/output pads consist of conductor backed co-planar waveguide (CBCPW). The filter is formed incorporating metallized through holes in low temperature co-fired ceramic (LTCC) substrates with relative dielectric constant of 7.05. The total volume of the filter including transitions is 4.5 mm2.65 mm0.4 mm. A fabricated DWGF with four transitions shows an insertion loss and a return loss of 2.95 dB and less than 15 dB at the center frequency of 62.17 GHz, respectively. According to the authors' knowledge, the proposed filter shows the lowest insertion loss among the embedded multi-layer millimeter-wave filters ever reported for 60 GHz applications.

The driving frequency dependence of EL characteristics were investigated in thick ceramic insulating type thin-film electroluminescent (TFEL) devices with various Mn-activated Y2O3-based phosphor thin-film emitting layers driven by a sinusoidal wave voltage. High luminous efficiencies of approximately 10 and 1 lm/W were obtained in the TFEL devices driven at 60 Hz and 1 kHz, respectively. The difference in luminous efficiency was mainly caused by the increase of input power in 1 kHz-driven-devices resulting from a dielectric loss of a thick BaTiO3 ceramic sheet used as the insulating layer. The correlation between the sound emission from the devices and the effective power consumed in the devices was found with variations in both the applied voltage and the frequency. The higher input power of the 1 kHz-driven-device may be attributable to sound emissions resulting from the piezo-electricity of BaTiO3 ceramics.

A negative thermal expansion ceramic substrate and an athermal fiber Bragg grating component with the substrate were subjected to reliability tests. We confirmed that the component has adequate durability for use as optical filters in the WDM system, under test conditions of damp heat, low temperature, mechanical shock and vibration. (50 words)

Fully embedded spiral inductors in a low loss dielectric multi-layer were designed and fabricated using a low temperature co-fired ceramics (LTCC) technology for RF SIP (system in package) integrations. The line width/space and the number of spiral layers were optimized within five layers of LTCC dielectric for high Q-factor, high self-resonant frequency (SRF), process easiness, and compact size. The embedded multi-layer spiral inductors reveal better performance in terms of Q-factor, SRF and the effective inductance Leff than planar spiral inductors of the same dimension and number of turns. The optimized multi-layer spiral inductor shows maximum Q of 56, Leff of 6.6 nH at Qmax and SRF of 3.6 GHz while planar spiral inductors have maximum Q of 49, Leff of 5.8 nH at Qmax and SRF of 3.0 GHz.

Although TE0nδ mode ceramic resonators are usually used at centimeter frequencies, they have difficulty in making wide-band band-pass filters in the millimeter-wave region due to the weak coupling factors between TE0nδ mode resonators and input/output waveguides. In order to overcome such difficulty, a band-widening technique of the ceramic resonator loaded band-pass filter has been proposed. The EHnmδ modes were regarded as spurious modes so far, but it is clear that the coupling factors are larger than those of the TE0nδ modes from the results of experimental considerations in this paper. By using the EH11δ mode ceramic resonators, 5-pole, 1 dB Chebyshev ripple NRD guide band-pass filter has been fabricated for the applications to broad-band millimeter-wave communication systems at 60 GHz. The filter has great advantages such as the wide pass-band beyond 2 GHz and low excess insertion loss of less than 0.3 dB.

Measurement of the viscosity of liquid using a piezoelectric disk is described. Experiments with a radial expansion mode of a piezoceramic disk were carried out for water-glycerin mixture samples. Resonant resistance has linearity to the square root of the product of density and viscosity of a liquid around 113 kHz.

A copper(Cu) thick film conductor containing glass and metal oxide for aluminum niride(AlN) substrate was developed. The conductor showed adhesion strength and reliability which were almost comparable to those of Ag-Pd conductors and also had good solder wettability and erosion properties. The Cu conductors must be fired in a nitrogen atmosphere containing oxygen gas. When they were fired under a low oxygen concentration, the gasses thermally decomposed and their properties changed which meant that the molten gasses could not flow smoothly to the AlN surface, so adhesion strength decreased. On the other hand, under high oxygen concentration, the adhesion strength increased because the thermal decomposition and property changes were suppressed. However, poorer solder wettability was brought about because copper was oxidized. Metal oxide added to the conductor could improve the wettability without decreasing the adhesion strength, even if it was fired at the higher oxygen concentration. Suitable metal oxides were CdO, Co3O5 and Fe2O3.

A Ku-band transversal filter with a center frequency of 12 GHz and a bandwidth of 6 GHz using directional couplers made of a multilayer ceramic has been proposed and developed. The directional coupler can realize a wide range of frequency characteristics, e.g. coupling of 3.50.5 dB in the frequency range of 10 to 17 GHz and a wide range of coupling values, i.e. 3 to 35 dB. Calculations have confirmed that the increase in insertion loss due to a decreasing Q-factor can be much less than that for a resonator filter. The transversal filter was fabricated without additional tuning, and measured results agreed well with calculated values.

This paper presents a new sort of multilayer piezoelectric ceramic transformer for switching regulated power supplies. This piezoelectric transformer operates in the second thickness extensional vibration mode. Its resonant frequency is higher than 1 MHz. First, numerical simulation was implemented using a distributed constant electromechanical equivalent circuit method. It was calculated that this piezoelectric transformer, which has higher than 200 mechanical quality factor Qm, could work with higher than 90% efficiency and in more than 20-W/cm3 high power density. Second, a trially fabricated transformer, which is 15 mm long, 15 mm wide and 2.2 mm thick, was examined. Modified PbTiO3 family ceramics were used for the piezoelectric transformer material, because of the large anisotropy between electromechanical coupling factors kt and kp. Obtained results indicate that the piezoelectric transformer has good resonant characteristics, with little spurious vibration, and exhibits 16-W/cm3 power density with high efficiency at 2 MHz. Moreover, a switching regulated power supply, applying the piezoelectric ceramic transformer, was built and examined.

A new built-in drive circuit for superconducting Josephson LSI circuits has been designed and fabricated in a ceramic multichip module. The drive circuit consists of an impedance matching circuit and a DC bias current feeding circuit to supply a two-phase power current to Josephson chips at a microwave frequency. The impedance matching circuit was designed based on a quarter wavelength stripline. A balanced stripline configuration was introduced to reduce the fluctuation of ground potential. Tungsten layers were used to make the drive circuit in a multilayer ceramic substrate of the multichip module. Whole circuit was successfully packed in a volume of 76 mm38 mm1.7 mm. The gain of microwave current were 20 dB around 1.2 GHz and 23 dB around 3.6 GHz, which were in good agreement with the simulated current gain.

This paper describes the effective countermeasures for exfoliation of large-sized ceramic capacitors, deterioration of dummy resistors and developement of a spark sensor with UVtrons at 300-500 kW transmitting stations. Cracks and exfoliation were found at the electrode of large-sized ceramic capacitors in the output circuit of the 500 kW transmitter. The exfoliation was caused by the temperature rise and the thermal fatigues at the electrode with the Nickel plating including Irons. A pure Nickel-plated electrode including no Irons and a new soldering method using disk-typed solder with a large adhesive area are employed in order to reduce the temperature rise. The temperature rise of the improved capacitor was 18 lower than the conventional one. Deterioration of ELEMA resistors of the 300 kW dummy antenna was discovered. The damage of the resistor was caused by the concentration of the electric current followed by the thermal stress cycle which made mechanical exhaustion at the electrode. Therefore, oval-shaped type resistors with much longer electric current path (20% up) to suppress the concentration of current flow and much slower temperature rise are newly developed. In case that sparks occurred at DC or RF high voltage impressed sections of the high power transmitting equipment, the discharged points could be seriously damaged by the transmitter energy itself. In orded to prevent this, a spark detector using UV (Ultra violet) trons is developed and installed at the matchign circuit of the 500 kW transmitter. Conventional UV sensors with only one UVtron could not detect feeble discharges and sparks with a duration time of less than 150 ms because of false outputs by the back ground noise. Since choosing three out of four UV trons system is employed, possibility producing a false output will be just one to 445 years theoretically. This means extremely reliable and sensitive spark detection system are constructed. These countermeasures have improved reliability of the transmitting equipment greatly. No damages have been found in the transmitters ever since.

In 1963, the authors began to develop a tuning circuit (hereafter referred to as the 'circuit') consisting of an inductor, fixed capacitors and a variable capacitor. The circuit required very high accuracy and stability, and the aging influence on resonant frequency needed to be Δf/f0 0.12% for 20 years. When we started, there was no methodology available for designing such a long-term stable circuit, so we reinvestigated our previous studies concerning aging characteristics and formed a design concept. We designed the circuit by bearing in mind that an inductor was subject to natural and stress demagnetization (as indicated by disaccommodation), and assumed that a capacitor changed its characteristics linearly over a logarithmic scale of time. (This assumption was based on short-term test results derived from previous studies.) We measured the aging characteristics of the circuits at room temperature for 20 years, from 1966. The measurement results from the 20-year study revealed that the aging characteristics predicted by the design concept were reasonably accurate.

We deal with a new type ceramic emitter which is used in a cleanroom ionizer system and is composed of a needle-shaped silicon and a rod-shaped silicon carbide ceramics. The discharge test was carried out to investigate the particle generation from the emitter and the degradation of the emitter. As a result, it was found that the ceramic emitter had practically higher performance than a conventional tungsten emitter.