A new patent insight report

8 November 2021

Quantum technologies and space

A new patent insight report published in early November reveals the extent of the growth in patent filings for the period 2001-2020 for quantum technologies (QT) related to space for earth observation, navigation and communication.

This report, which was drawn up by the European Patent Office (EPO) and the European Space Policy Institute (ESPI) in collaboration with the European Space Agency (ESA), investigates patent filing trends for quantum technologies applied in space.

Applications for quantum technologies in space are primarily in secure communications, time and frequency transfer, and earth observation and remote sensing. In its analysis, the report looks at three relevant quantum technology areas:

  • quantum key distribution (QKD), which uses quantum physics to secure the distribution of symmetric encryption keys
  • cold atom clocks (CAC), the most precise and accurate frequency standards
  • cold atom interferometers (CAI), which have the potential to revolutionise sectors such as navigation and positioning, natural resource exploration, geophysical studies and fundamental physics

The following chart illustrates how the report was compiled.

Patent insight report


  • Identify possible QT fields with application in space
  • Consult experts to confirm relevant space applications for QT
  • Create shortlist of topics of interest (QKD, CAC, CAI)
  • Separate search queries per topic
  • Develop individual search queries with balance between precision and recall
  • Identify and collect all QTpatent documents in the selected domains
  • Apply a filter to the collected dataset to identify inventions which are useful for QT space applications
  • Apply a space filter that uses a combination of space-related keywords, patent classifications and further high-level criteria to check suitability for space
  • Visualize dataset and trends
  • Identify connections, correlations and networks
  • Formulate insights, intelligence and conclusions

Using the example of secure communication with quantum key distribution (QKD), in this edition of Patent Knowledge News we will show you how you can carry out searches similar to those in the report using the search tools offered by the EPO.

You can use Espacenet to find relevant documents starting with keywords that are pertinent for this search topic: "QUANTUM KEY DISTRIBUTION" OR "QKD" OR "CVQKD" OR "QUBIT?" OR "Q BIT?" OR "QUANTUM BIT?" OR "ENTANGLE*". Examiners in the field recommend adding some protocol acronyms and projects: "BB84" OR "E91" OR "SAGA" OR "DARPA" OR "SECOQC". When combining these searches in "full text" (ftxt) search, however, we hit the search limits of Espacenet (10 search terms per field, 20 search terms in total), so we can search some terms in "All text fields or names" (nftxt) instead. As this search, which produces half a million documents, illustrates, searching in full text typically generates a lot of noise, since we also retrieve documents from different domains that simply mention the above technology. We therefore recommend combining your search terms with classification symbols, as this will allow you to limit the result list to inventions that our expert examiners have classified in the area of secure communication using key distribution, which is H04L9/08. We can also add publications from H04L9/0852, a specific class on quantum cryptography. The graph below shows how the resulting query results have developed over time.

enfigure1small

The more than tenfold increase in the 14 years from 2005 to 2019 in the number of patent families published annually as well as in cumulative filings shows just how important the topic of quantum technology in space has become.

Espacenet's filter module allows users to generate statistical analyses on many aspects such as protected markets, CPC subgroups, and main applicants and inventors and their countries of residence:

enfigure2small

Additional search criteria are needed when focussing on the inventions that are related to space. The following concept searches are run in Global Patent Index (GPI), which allows for very large search statements.

Concept 1: Quantum key distribution

(Word=("QUANTUM KEY DISTRIBUTION" OR QKD OR CVQKD OR CV +1W QKD OR QUBIT? OR QBIT? OR Q +1W BIT? OR QUANTUMBIT? OR QUANTUM +1W BIT? OR ENTANGLE* OR BB84 OR E91 OR SAGA OR DARPA OR SECOQC) and CLAS=H04L000908*) OR CLAS=H04L9/0852

Concept 2: Space-related

TIAB OR CLAIM=(AEROSPAC? OR AIRCRAFT?) OR WORD=(COSMIC* OR DEEP +1W SPACE OR OUTERSPACE OR OUTER +1W SPACE OR EARTHSTATION? OR EARTH +1W STATION OR GROUNDSTATION? OR GROUND +1W STATION? OR INTERPLANETAR* OR INTER +1W PLANETAR* OR MICROGRAVIT* OR MICRO +1W GRAVIT* OR SATELLITE? OR MICROSATELLITE? OR MICRO +1W SATELLITE? OR NANOSATELLITE? OR NANO +1W SATELLITE? OR SPACECRAFT? OR SPACE +1W CRAFT? OR SPACEVEHICLE? OR SPACE +1W VEHICLE? OR SPACESHIP? OR SPACE +1W SHIP? OR SPACESTATION? OR SPACE +1W STATION? OR SPACEBORNE OR SPACE +1W BORNE OR SPACE +1W PROBE? OR ZEROGRAVIT* OR ZERO +1W GRAVIT* ) OR CLAS=(B64G OR H01Q1/288 OR H04B10/118 OR H04B0007185*)

Global Patent Index also offers statistical analyses, e.g. on classification symbols such as the optical components for quantum communication in H04B10/70 The filings in this technical domain are further analysed in the report.

enfigure3small

You can find more details of the outcomes and findings in the Quantum technologies and space report. With its charts and commentary, the report will be of particular interest to scientists, engineers, companies and investors wanting to better understand these rapidly expanding technology domains. It also provides a deeper insight into the methodology used to arrive at these findings, applying a structured approach as set out in this article.

Quick Navigation