Lee De Forest's Early Radio Telegraphy System
A 1908 patent by radio pioneer Lee De Forest describing methods for transmitting and receiving wireless telegraphy signals using early vacuum tube technology.
Original patent title: “Space telegraphy.”
A 1908 patent by radio pioneer Lee De Forest describing methods for transmitting and receiving wireless telegraphy signals using early vacuum tube technology. Granted to FOREST RADIO TELEPHONE CO DE in 1908 with 2 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
This patent details a system for space telegraphy, which was the early term for wireless radio communication. It focuses on the hardware arrangement for generating and detecting electromagnetic waves across distances. By utilizing early components that would eventually evolve into the triode vacuum tube, the system allowed for the modulation of electrical signals to transmit information wirelessly through the air.
The gap
What does this patent NOT cover?
- Does not cover modern digital signal processing or binary data transmission.
- Does not cover the later invention of the Audion triode amplifier itself, which was patented separately.
- Does not cover satellite-based communication systems or modern cellular networks.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The patent explores the use of early electronic oscillation to create a more stable, continuous signal, which was a significant improvement over the noisy, broad-spectrum interference caused by primitive spark-gap transmitters.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Early wireless telegraphy stations
Pioneering radio broadcasting equipment
Why it matters
The bigger picture
Lee De Forest was a central figure in the birth of radio. This patent represents the foundational era of wireless communication, moving the industry away from spark-gap transmitters toward more controlled, continuous-wave transmission methods.
Filed
January 29, 1907
Granted
February 18, 1908
Market context
Who's building on this
Companies in this space
Modern telecommunications companies like Qualcomm and Nokia trace their technical lineage back to these early radio transmission principles. The fundamental physics of signal modulation established here remains the bedrock of all wireless infrastructure.
Market impact
This patent helped define the early radio industry, setting the stage for the massive commercial expansion of wireless telegraphy and eventually mass-market radio broadcasting in the 1920s.
Claim 1 — Plain English
What this patent covers
This patent details a system for space telegraphy, which was the early term for wireless radio communication. It focuses on the hardware arrangement for generating and detecting electromagnetic waves across distances. By utilizing early components that would eventually evolve into the triode vacuum tube, the system allowed for the modulation of electrical signals to transmit information wirelessly through the air.
The clever bit
The patent explores the use of early electronic oscillation to create a more stable, continuous signal, which was a significant improvement over the noisy, broad-spectrum interference caused by primitive spark-gap transmitters.
What it does not cover
- Does not cover modern digital signal processing or binary data transmission.
- Does not cover the later invention of the Audion triode amplifier itself, which was patented separately.
- Does not cover satellite-based communication systems or modern cellular networks.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Limited data
Citation count
10/40
Early citations
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$4K – $13K
Midpoint $8K · expired or expiring · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Concepts involved
Citations
Patent lineage
Cite this patent
Forest, L. D. (1908). Lee De Forest's Early Radio Telegraphy System (U.S. Patent No. 879,532). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/879532/de-forest-audion-vacuum-tube
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="US879532"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4405829 · 1983
How RSA Public-Key Encryption Keeps Digital Messages Secret
This patent describes the foundational RSA algorithm, a method for securely sending messages where anyone can encrypt a message using a public key, but only the intended recipient can decrypt it using a secret private key.
Massachusetts Institute of Technology
US 4575330 · 1986
How 3D Printers Build Objects Layer by Layer from Liquid
This patent describes the foundational method for 3D printing, where a machine builds a three-dimensional object layer by layer by hardening a liquid material with light or other energy.
UVP Inc
Semantically similar
You might also find these interesting
US 586193 · 1897 · Guglielmo Marconi
How Marconi Patented Early Wireless Telegraphy Signals
US 2524035 · 1950 · Bell Telephone Laboratories Inc
The Invention of the Transistor
US 1647 · 1840 · Samuel F. B. Morse
How Samuel Morse Patented the Electric Telegraph System
US 174465 · 1876
Alexander Graham Bell's Patent for the Telephone
More to explore
More in Telecom & Wireless
US 5347632 · 1994 · Prodigy Services Co
Prodigy's System for Interactive Online Information and Shopping
US 3906166 · 1975 · Motorola Inc
How Early Cell Phones Handled Calls Across Different Towers
US 4063220 · 1977 · Xerox Corp
How Multiple Computers Share a Network Cable Without Crashing
US 4200770 · 1980 · Leland Stanford Junior University
How to Create a Secret Code Key Without Meeting First
New to patents?
Common Questions
Frequently Asked Questions
What does Lee De Forest's Early Radio Telegraphy System cover?
A 1908 patent by radio pioneer Lee De Forest describing methods for transmitting and receiving wireless telegraphy signals using early vacuum tube technology.
Who owns patent US 879532?
FOREST RADIO TELEPHONE CO DE owns this patent, granted in 1908.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 879532 cited by?
This patent has been cited by 2 later patents that build on its ideas.
What problem does this patent solve?
Lee De Forest was a central figure in the birth of radio. This patent represents the foundational era of wireless communication, moving the industry away from spark-gap transmitters toward more controlled, continuous-wave transmission methods.
What does this patent NOT cover?
Does not cover modern digital signal processing or binary data transmission.
Patent monitoring