Kuniyoshi Yamane

Cruciform Directional Couplers in E-Plane Rectangular Waveguide

This paper proposes a new type of compact waveguide directional coupler, which is constructed from two crossed e-plane rectangular waveguide with two metallic posts in the square junction and one metallic post at each port. The metallic posts in the square junction are set symmetrically along a diagonal line to obtain the directivity properties. The metallic post inserted at each input/output waveguide port can realize a matched state. Tight-coupling properties 0.79-6dB is realized by optimizing the dimension of the junction and the positions/radii of the posts. The design results are verified by em-simulator (Ansoft HFSS)

A design of multi-stage, multi-way microstrip power dividers with broadband properties

We investigate a design method of multi-stage, multi-way microstrip power dividers to construct a compact low-loss power divider with number of outputs. First, we describe an integration design technique of multi-way power dividers founded on the planar circuit approach in combination with segmentation method, and design broadband 3- and 4-way power dividers. Next, we successfully design a 9-way power divider consisting of 3-way dividers of two-stage structure using a similar technique. As a result, the fractional bandwidths of nearly 90%, 100%, and 85% are obtained, respectively. The validity of these design results is confirmed by HFSS and an experiment.

Analysis of Post-Wall Waveguide by H-Plane Planar Circuit Approach

A waveguide whose side walls are formed of densely arranged metallic posts has been proposed and applied to antennas etc. for millimeter-wave. This paper suggests an analytical method of the post-wall waveguide or the substrate integrated waveguide by applying the analysis technique of the H-plane waveguide discontinuities based on the planar circuit approach. The analytical procedure consists of the derivation of the mode impedance matrices for regular-shaped circuits and short-circuiting fictitious ports arranged at the peripheries of the metallic posts. First, a straight section of the post-wall waveguide is treated as an example and the analysis method is described. Then the S-parameters of the guide are calculated. Next, the analysis method is applied to the design of a right-angled corner with an air post. The analysis and the design results are verified by an em-simulator (HFSS).

Design of Cruciform Directional Couplers in E-Plane Rectangular Waveguide

This paper proposes a new type of compact waveguide directional coupler, which is constructed from two crossed E-plane rectangular waveguide with two metallic posts in the square junction and one metallic post at each port. The metallic posts in the square junction are set symmetrically along a diagonal line to obtain the directivity properties. The metallic post inserted at each input/output waveguide port can realize a matched state. Tight-coupling properties 0.79 - 6dB are realized by optimizing the dimension of the junction and the positions / radii of the posts. The design results are verified by em-simulator (Ansoft HFSS).

Multi-Stage, Multi-Way Microstrip Power Dividers with Broadband Properties

We investigate a design method of multi-stage, multi-way microstrip power dividers to construct a compact low-loss power divider with number of outputs. First, we describe an integration design technique of multi-way power dividers founded on the planar circuit approach in combination with segmentation method, and design broadband 3- and 4-way power dividers. Next, we successfully design a 9-way power divider consisting of 3-way dividers of two-stage structure using a similar technique. As a result, the fractional bandwidths of nearly 90%, 100%, and 85% are obtained, respectively. The validity of these design results is confirmed by HFSS and an experiment.

FDTD analysis of an obliquely magnetized YIG film microstrip line

Overall transmission characteristics of a microstrip line with an obliquely magnetized YIG-GGG thin film substrate including both the quasi-TEM and the MSW modes are investigated by using the finite-difference time-domain (FDTD) method solving the equation of motion of the magnetization vector simultaneously with the Maxwells equations in consistency. Nonreciprocal transmission characteristics of a microstrip line with an obliquely magnetized YIG-GGG film substrate normalized by fifty ohm are directly calculated by the FDTD method. The results are agreeable to the experimental results.

FDTD analysis of a microstrip line with YIG film magnetized in arbitrary direction

The overall transmission characteristics of a microstrip line with a YIG-GGG thin film substrate magnetized in arbitrary direction are investigated by using the finite-difference time-domain (FDTD) method including the hybrid mode of electromagnetic and magnetostatic modes. Transmission characteristics of a microstrip line with a YIG-GGG film substrate normalized by fifty ohm are directly calculated, which are agreeable with the experimental results.

Full-wave FDTD analysis of transmission characteristics of a microstrip line with a YIG thin film substrate

We investigate overall transmission characteristics of a microstrip line with a YIG thin film substrate including both the quasi-TEM and MSFVW modes by using the FDTD method solving the Maxwells equations simultaneously with equation of motion of the magnetization vector in consistency, which is useful for the circuit design and packaging. A profile of a mechanism of excitation of the MSFVW in the microstrip line is shown in sequence of time and in a point of view of the attenuation frequency range of the transmission characteristic in comparison with the result of the conventional theoretical approach with magnetostatic approximation. The transmission characteristic agreed well with the experimental result and the validity of the FDTD result has been confirmed.

Broadband Multi-Way Microstrip Power Dividers

This paper treats multi-way microstrip power dividers composed of multi-step, multi-furcation, and comers. Since the design procedure is founded on the planar circuit approach in combination with the segmentation method, optimization of the circuit configuration can be performed in a reasonable short computation time when applying the Powells optimization algorithm. Actually, broadband 3- and 4-way power dividers with mitered bends are designed, and fractional bandwidths of about 90% and 100% are realized for the power-split imbalance less than 0.2 dB and the return loss better than -20 dB, respectively. The validity of the design results is confirmed by an EM-simulator (HFSS) and experiments.

Parallel processing of Powell's optimization algorithm and its application to design of multi-way power dividers

In the case of optimizing the circuit configurations such as multi-way power dividers, the planar circuit approach is useful because of its merit of short calculation time. However, as the number of design variable increases, the CPU time required in the optimization becomes large. This paper describes a parallel computing technique of Powells optimization algorithm using a PC-cluster, and applies to an integration design of microstrip multi-way power dividers. As a result, it is shown that the parallel processing technique can speed up the circuit optimization with facility.