Terahertz Waveguide

Our high-precision micro-machining technology enables us to cut grooves down to the micron level by making full use of our expertise in machine control and machining tools.

The key to achieving the performance of a waveguide is dimensional accuracy and surface roughness processing. Accordingly, the ultimate in processing accuracy makes it possible to achieve excellent high-frequency and communication characteristics.

Our customers, including the National Astronomical Observatory of Japan (NAOJ), have been requesting higher-level components that can not be realized without the challenge of innovating microfabrication technology year by year.

We are grateful for the opportunity to improve our processing technology and to be part of our customers’ latest technological innovations.

[Grooving and cylindrical inner diameter machining with micrometer-level accuracy]
To meet our customers’ demands, we will build a processing method that matches the shape to guarantee the physical dimensions. Our customers have confirmed their products’ electrical characteristics to be as designed, proving the accuracy of our products.

[Complex Processing Technology]
We make full use of lathes, machining centers, wire processing, and brazing to achieve shapes that meet our customers’ requirements.

The following are examples of our micromachining process. The SEM photos are used through the courtesy of the National Astronomical Observatory of Japan (NAOJ).

275 to 500GHz-Band Directional Coupler

Slit groove width: 0.035mm, Depth: 0.4mm
Accuracy: ±0.005mm
Material: Tellurium copper

Initially, we verified the processing with EDM as well as machining. As a result, we found that EDM generated a step on the bottom surface due to the EDM gap, but with machining, we were able to cut with precision without creating any steps.

This was the first time we had ever tried to process grooves with an end mill L/D ratio of more than 10 times. And we were able to realize this process by using a small diameter end mill and controlling the infeed of depth in micrometers.

400GHz-Band Frequency Multiplexer

Slit (48 locations) Groove width: 0.058mm, Depth: 0.28mm, Wall width (48 locations): 0.06mm
Accuracy: ± 0.005mm
Material: A6061

This product has a shape with multiple grooves of 0.058mm in width and 0.06mm in wall width, with a high degree of difficulty, but our customer was satisfied with its excellent characteristics.

We have achieved the process by installing multiple small-diameter end mills on the machine and controlling the infeed depth of cut in micrometers while switching blades in light of the blade life.


Photo: the courtesy of NAOJ	Photo: the courtesy of NAOJ

1.4THz Corrugated Horn

Groove width: 0.034mm, Depth: 0.08mm
Accuracy: ±0.005mm
Number of grooves: 134
Material: A6061

After creating a tapered shape using a custom-made tool, the amount of cutting was controlled by the micrometers unit at a time using a customized grooving tool.

With the successful machining of 1.4THz, our customers expect us to achieve corrugated horns for even higher frequencies. We are currently trying to process the next version of the product.

	Photo: the courtesy of NAOJ
Photo: the courtesy of NAOJ

900GHz Corrugated Horn

Groove width: 0.054mm, Depth: 0.129mm
Accuracy: ±0.005mm
Number of grooves: 133
Material: A6061

After creating a tapered shape using a custom-made tool, the amount of cutting was controlled by the micrometers unit per cut using a customized grooving tool.
This part is installed on the ALMA telescope in Chile.

140GHz-Band Mixer Block

Groove width: 0.15mm and 0.23mm, Depth: 0.825mm
Accuracy: ±0.01mm
Material: Tellurium copper
Surface treatment: gold plating

We realized this processing by controlling the infeed depth by the micrometers unit per cut using an end mill.

This part is installed on the ALMA telescope in Chile.

500GHz-Band Waveguide (Circular Polarization Separator)

Waveguide filter slit width: 0.072mm, Depth: 0.1mm
Accuracy : ±0.005mm
Material: A6061

This product consists of nine parts, and the position accuracy of each block and the machining accuracy of the two central parts (waveguide filter) are essential.

In order to achieve the position accuracy of the blocks, ultra-precision blocks with ±0.002mm accuracy were produced by six-sided polishing on the material, and the blocks with concavo-convex were combined.

Except for the two outer parts, the parts were processed from the ultra-precision blocks.

Overall View

Waveguide Filter Section

(Reference) The research results using this waveguide is reported in a paper by Osaka Prefecture University.

Novel 500-GHz Band Waveguide Stepped Septum-Type Circular Polarizer with a New High-Accuracy and Very Small Waveguide Flange