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


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
(in practical use)

collaboration with TOKYO ELECTRON (TEL)



*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


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

for Entrance Radio Relay

comments on slotted waveguide arrays
comments on T-junctions


*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]

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

Slotted Parallel Plate Post-Wall Waveguide Array


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%)
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

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

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