Research

Antennas

Our research themes are planar slotted waveguide antennas and electromagnetic theory.

Radial Line Slot Antenna (RLSA)

*DBS^ Reception** *DBS: Direct Broadcast from Satellite	DBS Reception Antenna High Efficiency, 12GHz, 34dBi, Antenna Efficiency 85% （in practical use） collaboration with TOPPAN comments on coaxial mode
Millimeter-Wave	Small Aperture for Wireless LAN Waveguide Fed RLSA (38GHz) comments on rotational mode
Millimeter-Wave Wireless LAN	for Wireless LAN (38GHz, 26dBi, 300Mbps) collaboration with CRL and OKI
Plasma Etching	30cm Diameter Order Large Aperture Plasma Equipment (8.3GHz) （in practical use） collaboration with TOKYO ELECTRON (TEL)
SSPS^* *SSPS: Space Solar Power System	A Radial Line Slot Antenna Fed by a Rectangular Waveguide through a Crossed Slot (5.8GHz, 23dBi, 300W) collaboration with IHI and Kyoto University comments on rotational mode

Single-Layer Slotted Waveguide Arrays

Millimeter-Wave	High Efficiency, 35dBi(60GHz 64%, 76GHz 56%) Alternating-phase Feed Single-Layer Slotted Waveguide Array comments on slotted waveguide arrays comments on T-junctions
High Frequency Radio Systems (20-50GHz)	for Entrance Radio Relay comments on slotted waveguide arrays comments on T-junctions
FWA^* *FWA: Fixed Wireless Access	FWA Antenna (26GHz, Alternating-phase) （in practical use） collaboration with Japan Radio Co., Ltd. (JRC) comments on slotted waveguide arrays comments on T-junctions [Related Link] JRC 26GHz FWA TECHNOLOGY
Mobile DBS Reception Antenna	Waveguide Crossed Slot Array 11.85GHz, 26.5dBi, Circularly Polarized Wave Leaky-wave excitation, Beam-Tilting Angle: 52deg （in practical use） collaboration with Nippon Steel Corporation comments on crossed-slot arrays comments on pi-junctions




Feed Circuits	Pi-Junctions for Co-Phase Feed T-Junctions for Alternating-Phase Feed Cross-Junctions for Center Feed

Slotted Parallel Plate Post-Wall Waveguide Array

Feature	PCB^* Technology Metalized via holes in PCB for waveguide structures Etching for slots *PCB: Print Circuit Board comments on parallel plate post-wall waveguide
Millimeter-Wave (76GHz)	High efficiency, (30dBi, 45%), (35dBi, 40%)
RADAR	Side lobe supression by Taylor distribution 77GHz, -22dB (E-plane or H-plane), -18dB (E and H planes)

Slotted Parallel Plate Array （60GHz）

A Beam Switching Slot Array with a 4-Way Butler Matrix Installed in a Single Layer Post-Wall Waveguide （26GHz）

comments on Butler matrix

Convertors	Connection between millimeter-wave RF circuits and antennas (waveguide feed, planar circuit feed)

Electromagnetic Theory
　

High Frequency Diffraction Theory

Analysis of scattering and diffraction phanomena by geometrical optics (GO)

Fictitious Penetrating Rays in PO

Fictitious Penetrating Rays at a Corner of a Reflector

Equivalence of physical optics (PO) and aperture field integration method (AFIM)
Mathematical derivation of modified edge representation (MER)

Visualization of high frequency diffraction based on physical optics and stationary phase (SP) method (Animation of Circular Disk: 212K, Animation of Square Plate: 119K)

Visualization of scatterd field from a square plate

Radiation pattern analysis of antennas on a finite ground plane

RLSA with finite ground plane

High Frequency Diffraction Theory
Analysis of scattering and diffraction phanomena by geometrical optics (GO)
Fictitious Penetrating Rays in PO Fictitious Penetrating Rays at a Corner of a Reflector
Equivalence of physical optics (PO) and aperture field integration method (AFIM) Mathematical derivation of modified edge representation (MER)
Visualization of high frequency diffraction based on physical optics and stationary phase (SP) method (Animation of Circular Disk: 212K, Animation of Square Plate: 119K) Visualization of scatterd field from a square plate
Radiation pattern analysis of antennas on a finite ground plane RLSA with finite ground plane