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Shintaro Uda: The Experimental Half of the Yagi-Uda Antenna

By Infinite Creation · Profile

At a Glance

Shintaro Uda (1896-1976) carried out the experiments at Tohoku Imperial University that established how parasitic elements placed near a driven dipole produce directional gain. The antenna is the Yagi-Uda. In English it is usually just "the Yagi". He is in this corpus as the clearest small-scale illustration of how publication language allocates credit.

Lived: 1896-1976, Japan
Anchor year: 1926, the experimental work
Strand: overlooked, the name that dropped off

Career

The problem as it stood

The idea that a nearby conductor might re-radiate and shape a pattern was not, by itself, enough. What lengths? What spacings? How many? Without answers the concept is not an antenna design, and answering them meant systematic measurement at short wavelengths in the 1920s.

What he actually did

Uda ran the experimental programme, publishing a series of papers in Japanese from 1926 that worked out the behaviour of reflectors and directors and the effect of varying their length and spacing. This is the work that turned the principle into something an engineer could build to specification.

How it worked

The measurements established the sensitivity of the design to element length and spacing, that a director must be shorter than the driven element and a reflector longer, and roughly by how much. That is the difference between a physical curiosity and a manufacturable component.

What it made possible

A design specification that could be reproduced anywhere, which is why the antenna spread so fast once Yagi published it in English. Uda continued in antenna research and became a professor at Tohoku.

What happened to him

He remained an academic in Japan and published extensively in Japanese. He and Yagi both died in 1976. In Japan the joint attribution is standard. In English it usually is not.

Where the credit landed

Uda published first, in Japanese, from 1926. Yagi published in English in 1928 and held the patent. Yagi credited Uda, and the correct name of the design has always been the Yagi-Uda. The shortening to "Yagi" happened in Anglophone usage, not by either man's doing. This is the linguistic erasure mechanism operating on someone who was neither obscure nor uncredited: merely publishing in the wrong language for posterity.

Known For

Uda published first. Yagi published in English.
Working out the dimensions is the engineering: the concept alone is not a design.
Correct usage is Yagi-Uda.

Knowledge Base

What You'll Learn

Uda is the control case for the corpus's claims about language and credit.

Why this one is unusually clean

Most erasure in this corpus involves a corporation, a contract or a patent fight. Here there was none of that: no employer absorbed the work, no anonymity clause applied, and the senior colleague actively credited the junior one. The name still dropped out of English usage. That makes Uda useful evidence that language alone is sufficient to erase a contributor.

Where This Fits

Uda's experiments shaped the reception aerial, the far end of the chain covered in A History of Broadcast Technology.

FAQ

Q: Did Yagi take credit for Uda's work?
A: No. Yagi credited Uda, and the design has always properly been called the Yagi-Uda antenna. The shortening to "Yagi" is a feature of English-language usage rather than an act by either man.

Q: What did Uda contribute specifically?
A: The experimental programme, published from 1926, establishing how parasitic reflectors and directors behave and how element length and spacing determine the pattern: the work that made the design reproducible.

Vocabulary

Directivity. How strongly an antenna favours one direction over others. Concentrating reception on the wanted signal and away from interference, which matters most where the wanted signal is weak.

Parasitic element. A conductor near a driven antenna element, with no connection of its own, that reshapes the pattern. Cheap to add and remarkably effective, which is why the design became ubiquitous.

Director and reflector. Parasitic elements placed in front of and behind the driven element. The director draws the pattern forward and the reflector blocks the rear, sharpening the antenna's focus.

Gain. In an antenna, how much stronger the signal is in the favoured direction compared with one radiating equally everywhere. Comes entirely from concentration rather than from any amplification.

Sources

The patent record was checked directly, because it is the reason the Western name for this antenna is incomplete. Checked 20 August 2026.

US Patent 1,860,123, Variable Directional Electric Wave Generating Device. The US patent covering the antenna, filed 3 September 1926 and granted 24 May 1932. Hidetsugu Yagi is the sole named inventor and Uda does not appear, despite having done the principal experimental work.