New strip arrangements for high Q or high effective permittivity are proposed for artificial dielectric resonators in a waveguide. The quality factor and the effective permittivity are discussed by changing strip arrangement composing the artificial dielectric. Concentrating strips from both sides to the middle in the waveguide leads to increase of unloaded Q. The value becomes high to several thousands by decreasing dielectric loss of the material. Interdigital strip arrangement makes the effective permittivity very high. A resonator of the strip arrangement has effective permittivity over 800 and unloaded Q over 1000. Moreover the resonator exhibits a good spurious characteristic with no unnecessary resonant mode throughout several harmonics range.

A millimeter wave BPF constructed from the WG mode dielectric disk resonators is presented. The design chart for the high Q WG mode resonator is obtained from Qu calculation of some WG modes. By using the design chart, high Q WG mode resonator having no influence of unwanted higher order resonances is designed. Designed resonators have different diameter and various Resonance Frequency Separation respectively. A 3 stage maximally flat BPF is constructed so that each resonator may be coupled laterally on the edge of the disk. Designed center frequency is 62.47 GHz and 3 dB bandwidth is 100 MHz. As a result, this BPF has insertion loss of 1.5 dB and some spurious responses which were existed conventional WG mode BPF are reduced considerably.

A NRD guide fed dielectric lens antenna with high gain and low sidelobe characteristics is proposed for millimeter wave applications. The measured results showed very good performance at 60 GHz. It exhibited a gain of 24.9 dBi, 27 dB sidelobe level suppression.

Traveling electromagnetic waves on infinite linear periodic arrays of lossless penetrable spheres can be conveniently analyzed using the source scattering-matrix framework and vector spherical wave functions. It is assumed that either the spheres are sufficiently small, or the frequency such, that the sphere scattering can be treated using only electric and magnetic dipole vector spherical waves, the electric and magnetic dipoles being orthogonal to each other and to the array axis. The analysis simplifies because there is no cross-coupling of the modes in the scattering matrix equations. However, the electric and magnetic dipoles in the array are coupled through the fields scattered by the spheres. The assumption that a dipolar traveling wave along the array axis can be supported by the array of spheres yields a pair of equations for determining the traveling wave propagation constant as a function of the sphere size, inter-sphere separation distance, the sphere permittivity and permeability, and the free-space wave number. These equations are obtained by equating the electric (magnetic) field incident on any sphere of the array with the sum of the electric (magnetic) fields scattered from all the other spheres in the array. Both equations include a parameter equal to the ratio of the unknown normalized coefficients of the electric and magnetic dipole fields. By eliminating this parameter between the two equations, a single transcendental equation is obtained that can be easily solved numerically for the traveling wave propagation constant. Plots of the k - β diagram for different types and sizes of spheres are shown. Interestingly, for certain spheres and separations it is possible to have multiple traveling waves supported by the array. Backward traveling waves are also shown to exist in narrow frequency bands for arrays of spheres with suitable permittivity and permeability.

This paper presents a technique for designing a dielectric Electronically Steerable Parasitic Array Radiator (Espar) antenna to achieve miniaturization of the conventional Espar antenna. The antenna's size is reduced by immersing the central active element in a dielectric cylinder, mounting the surrounding planar parasitic elements at the circumference of the cylinder, and decreasing the radius of the ground skirt to that of the parasitic elements. An example of a polycarbonate (εr = 2.9 + j0.006) Espar antenna operating at 2.484 GHz is optimised by using a genetic algorithm in conjunction with an FEM-based cost function. The designed antenna generates a half-power beam width of 78and a main lobe that elevates at an angle of only 5from the horizontal plane. The designed antenna is also fabricated and measured. Good agreement between the measurement and simulation results is obtained. We reduce the size of the designed Espar antenna to 1/8 the size of its conventional counterpart while achieving a 12improvement in half-power beam width.

A method is presented for the simultaneous measurement of the absolute gain of antennas in solution and the dielectric properties of the solution. The principle and formulation are based on a modified Friis transmission formula. This three-antenna method is applied to gain measurement of printed dipole antennas in solution, and demonstrated through comparison with calculated results to be an accurate method for the measurement of both antenna gain and solution dielectric properties.

The problems with the CV characterization on very leaky (thin) nitrided oxide are mainly due to the measurement precision and MOS gate dielectric model accuracy. By doing S-parameter measurement at RF frequency and using simple but reasonably accurate model, we can obtain proper CV curves for very thin nitrided gate dielectrics. Regarding the measurement frequency we propose a systematic method to find a frequency range in which we can select measurement frequencies for all biases to obtain a full CV curve. Moreover, we formulated the first order relationship between the measurement frequency range and the test structure design for CV characterization. With the established formulae, we redesigned the test structures and verified that the formulae can be used as a guideline for the test structure design for RFCV measurements.

We investigated the use of AlOx:N/SiNy stacked gate dielectric as an alternate gate dielectric, which were prepared by alternately repeating sub-nanometer deposition of Al2O3 from an alkylamine-stabilized AlH3 + N2O gas mixture and rapid thermal nitridation in NH3. The negative fix charges, being characteristics of almina, were as many as 3.91012 cm-2 in the effective net charge density. The effective dielectric constant and the breakdown field were 8.9 and 8 MV/cm, respectively, being almost the same as pure Al2O3. And we have demonstrated that the leakage current through the AlOx:N/SiNy stacked gate dielectric with a capacitance equivalent thickness (CET) of 1.9 nm is about two orders of magnitude less than that of thermally-grown SiO2. Also, we have confirmed the dielectric degradation similar to the stress-induced leakage current (SILC) mode and subsequent soft breakdown (SBD) reported in ultrathin SiO2 under constant current stress and a good dielectric reliability comparable to thermally-grown ultrahin SiO2. From the analysis of n+poly-Si gate metal-insulator-semiconductor field effect transistor (MISFET) performance, remote coulomb scattering due to changes in the gate dielectric plays an important role on the mobility degradation of MISFET with AlON/SiON gate stack.

We have developed an estimation system of the electric parameters for liquid materials without a sensor connecting to the testing materials. A PC can be used for the calculation, and the calculation time is about 2 minutes. The accuracy is such that the estimated values are different from the nominal values by less than 2%.

Unloaded Q of a dielectric image resonator is discussed based on the electromagnetic field distribution. It is shown that a partial air gap and a dielectric sheet with low permittivity between the dielectric resonator and the shield case reduce both the dielectric loss and the conductor loss. Especially, reduction of the conductor loss is significant, since the magnetic field distribution moves from the conductor to the upper part of resonator. A half-cut image resonator with an air gap and dielectric spacer is simulated and measured. The unloaded Q of the dielectric resonator with low dielectric loss is improved by about two times from that of original image resonator.

A miniaturized rectangular resonator made of a novel anisotropic artificial dielectric material is investigated which has advantages of small size and big separation of the higher-modes. To obtain a property of anisotropic permittivity, artificial dielectric material is fabricated by lamination of rectangular metal strips etched on a printed circuit board. Artificial dielectric rectangular resonators are designed to excite TE10δ mode selectively, aligning the rectangular metal patterns along the direction of the mode electric field line. The resonant frequencies and coupling coefficient of artificial dielectric rectangular resonators encapsulated in a metal waveguide are analyzed theoretically, and compared with the experimental result. As a microwave application, a high selectivity TE10δ mode bandpass filter (BPF) using two artificial dielectric rectangular resonators is demonstrated. A two-stage BPF with the center frequency of 1.718 GHz, bandwidth of 78 MHz, and insertion loss of 1.3 dB is successfully realized in a rectangular waveguide.

It is known that a high permittivity NRD guide suffers from irregular transmission phenomena. In this study, we clarified that this problem is caused by a mode coupling phenomenon between the operating and parasitic modes due to a small remaining asymmetrically air gap between the metal plates and high permittivity dielectric materials.

A flexible transmission line, consisting of a thin ceramic-compounding Teflon strip, was devised by using a high permittivity LSE-NRD guide. This transmission line has the advantage of changeable shape. Low-loss performance was confirmed by measuring the transmission loss of the 180 degree bend and the S-shaped curve in the 60 GHz frequency band.

A high permittivity LSE-NRD guide was applied to a planar antenna at 60 GHz. Emphasis was placed on compatibility between the high permittivity LSE-NRD guide and the conventionally used low permittivity LSM-NRD guide. Performance of the transition between two such types of NRD guides was optimized by using an electromagnetic simulator and the validity was experimentally demonstrated. A simple radiator, consisting of a tapered high permittivity LSE-NRD guide was fabricated and evaluated as to radiation characteristics. Since the radiator has a broad radiation pattern, it was employed in a primary radiator of a two-dimensional parabolic reflector to develop a new type of folded planar antenna at 60 GHz. This planar antenna has a double-layered structure. In the upper layer, a metalized dielectric substrate with a slotted array is excited by a rectangular-shaped oversized waveguide, and in the lower layer, an offset parabolic reflector is fed by the radiator. Measurement showed the half-power beam width of the fabricated antenna to be 2.5 degrees in the E and H planes, respectively, and the gain to be 35.3 dBi, thus indicating that a good pencil beam antenna was successfully developed in this manner.

Recently, dielectric lens antennas are paid attentions in ITS applications. Many lens shape designing methods were already developed. And electrical performances were estimated through a ray tracing method. Here, arbitral lens shapes were expressed by a system of power series. In the case of ray tracing, time-consuming three-coordinate root-finder programs were needed to find intersection points of rays on the lens surfaces. In order to calculate complicated structures such as zoned lenses and complicated rays such as multiple reflections between lens surfaces, simple ray tracing methods are requested. In this paper, a simple ray tracing method that utilizes directly designed discrete points of lens surfaces is developed. In this method, a refracted ray is automatically determined for a given incident ray. As for an intersecting point of a lens surface for an outgoing ray, the nearest point to the refracted vector is found out by employing a simple searching procedure. This method is time-saving compared to the previous three-coordinate root-finding program. Through calculated results of focal points and radiation patterns in wide angle beam steering, effectiveness of a developed method is ensured. Application of the developed ray tracing method of complicated multiple reflections are studied. Reflecting points are found out speedily by the same searching procedure. A calculated example of doubly reflected rays is obtained. Through comparing calculated and measured results of wide angle radiation patterns, effectiveness of a developed method is ensured.

Novel high-frequency asymptotic solutions for the scattered fields by a dielectric circular cylinder with a radius of curvature sufficiently larger than the wavelength are presented in this paper. We shall derive the modified UTD (uniform Geometrical Theory of Diffraction) solution, which is applicable in the transition regions near the geometrical boundaries produced by the incident ray on the dielectric cylinder from the tangential direction. Also derived are the uniform geometrical ray solutions applicable near the geometrical boundaries and near the caustics produced by the ray family reflected on the internal concave boundary of the dielectric cylinder. The validity and the utility of the uniform solutions are confirmed by comparing with the exact solution obtained from the eigenfuction expansion.

An image NRD guide-fed dielectric rod antenna, which is suitable for use at millimeter-wave frequencies, is presented in this paper. The antenna is composed of a linearly tapered dielectric rod connected to the image NRD guide. First, radiation characteristics of the dielectric rod antenna directly protruded from the end of the image NRD guide are investigated by FDTD analysis and measurements at 30 GHz band. For this case, the degradation of the radiation pattern and the decrease of the gain, which are due to the strong radiation from the guide-to-antenna discontinuity, are observed. In order to minimize this radiation and to realize reasonable radiation characteristics, a transition from the image NRD guide-to-rod antenna is proposed. A simple procedure to determine the optimum dimensions of the transition is described. This procedure is based on parametric study of the transition's dimensions, and is performed using FDTD analysis. Based on the results, the dielectric rod antenna having a length of 10 λ0 is designed, and its performance is analyzed and measured. The results show that radiation patterns with the half power beamwidth of 22, sidelobe level of -21 dB and reasonable gain of 18.5 dBi can be realized by employing the transition having the optimum dimensions.

This paper presents a new method to improve the resonant characteristics of a microstrip resonator. The improved characteristics have been achieved by inserting two dielectric rods between strip conductor and the ground plane. Dielectric rods to be inserted have higher relative permittivity than that of the substrate. Therefore, it is suitable to realize by Low-Temperature Cofired Ceramics (LTCC) technique. Several model of microstrip resonators employing the proposed method are analyzed by a Finite-Difference Time-Domain (FDTD) method, and their resonant characteristics are discussed. One of the advantages of the proposed method is that an attenuation pole (fl or fh) in each side of the fundamental resonant frequency (fr) and improved-spurious responses can be realized together by a capacitive-coupling tapped resonator loaded with dielectric rods. The proposed method is also effective to achieve sharp skirt characteristics and wide stopband of a direct-coupling tapped resonator which can be used either as a wideband lowpass filter or a band-elimination filter. Another interesting feature of the analyzed resonators is that about 60% reduction in resonator's length has been obtained compared to a basic half-wavelength (λ/2) microstrip resonator. Therefore, wide exploitation of the proposed method can be expected in the filter design based on the LTCC technique.

This paper proposes a PCB plane model for generic circuit simulators (SPICE). The proposed model reflects two frequency-dependent losses, namely, skin and dielectric losses. Once power/ground plane pair is divided into arrays of unit-cells, each unit-cell is modeled using a transmission line and the loss model. The loss model is composed of a resistor for DC loss, series RL ladder circuit for skin loss and series RC ladder circuit for dielectric loss. To verify the validity of the proposed model, it is compared with SPICE ac analysis using frequency-dependent resistors. Also, we show that the estimation results using the proposed model have a good correlation with that of VNA measurement for the typical PCB stack-up structure of general desktop PCs. With the proposed model, not only ac analysis but also transient analysis can be easily done for circuits including various non-linear/linear devices since the model consists of passive elements only.

The complex dielectric image Green's function for metal-insulator-semiconductor (MIS) technology is proposed in this paper through dielectric image method. Then the Epsilon algorithm for Pade approximation is used to accelerate the convergence of the infinite series summation resulted from the complex dielectric image Green's function. Because of the complex dielectric permittivity of semiconducting substrate, the real and imaginary part of the resulted Green's function is accelerated by Epsilon algorithm, respectively. Combined with the complex dielectric image Green's function, the frequency-dependent capacitance and conductance of the transmission lines and interconnects based on MIS technology are investigated through the method of moments (MoM). The computational results of our method for 2-D and 3-D extraction examples are well agreement with experimental data gained from chip measurement and other methods such as full-wave analysis and FastCap.