PopHorn: A deployable folding horn antenna for low frequency space-based applications
Lead Research Organisation:
UNIVERSITY OF MANCHESTER
Department Name: Physics and Astronomy
Abstract
Different shapes and types of radio antennas are useful in different circumstances. Horn-shaped antennas are particularly good for when a very accurate calibration of some radio instrumentation (e.g. a radio telescope) is needed, for example. This makes horn antennas very popular for many different applications at microwave frequencies, where they only need to be a few centimetres (or tens of centimetres) across. At low frequencies, a horn antenna would have to be gigantic to work in the same way however. This large size limits their usefulness, particularly for space-based applications where there are restrictive requirements on size and weight of the payloads. We will develop a type of folding antenna that can be packaged up into a relatively small and lightweight form suitable for attaching to a spacecraft, but which folds out into a large horn antenna shape when deployed, suitable for low-frequency applications. This will make it practical to do very high precision radio measurements at low frequencies from space.
Publications
Bull P
(2025)
RHINO: a large horn antenna for detecting the 21 cm global signal
in RAS Techniques and Instruments
| Title | RHINO antenna patterns |
| Description | Simulated antenna patterns for the RHINO horn antenna experiment. These antenna patterns were simulated using CST Studio. They may be used under a CC-BY-SA 4.0 license, credited to "A. El-Makadema, on behalf of the RHINO Collaboration". |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | We have made our full EM simulations of antenna patterns available to the public, which we believe is unique for this type of experiment. |
| URL | https://github.com/RHINO-Experiment/rhino-beams |
| Description | Genetis antenna optimisation collaboration |
| Organisation | National Aeronautics and Space Administration (NASA) |
| Department | Jet Propulsion Laboratory |
| Country | United States |
| Sector | Public |
| PI Contribution | As part of our STFC-funded research, we have developed a pipeline to simulate 21cm global signal experiment data, which can include the effects of arbitrary angular beams. |
| Collaborator Contribution | Our collaborators at JPL and Ohio State University have a code called GENETIS, based on genetic algorithms, which is capable of evolving antenna design to optimise certain objective criteria. As a result of conversations started within the context of our STFC-funded work, we have developed a new active collaboration, and are pursuing a research project together wherein JPL will connect their genetic algorithm code to our 21cm global signal simulator to optimise antenna designs based on complex data-related criteria. |
| Impact | No outputs yet. This is multi-disciplinary, between astronomers (us) and electrical engineering/modelling experts (JPL and Ohio State). |
| Start Year | 2023 |
| Title | Deployable horn antenna |
| Description | We have developed a technology to deploy a large horn antenna from an initially small package attached to a satellite platform. |
| Type Of Technology | New/Improved Technique/Technology |
| Year Produced | 2025 |
| Impact | The technology was featured as the basis of a UKSA white paper submission in 2025. |
| Title | Hydra |
| Description | Hydra is a code that implements a statistical model of complex visibility data from radio telescope arrays that target the 21cm line from neutral hydrogen. Once the 21cm signal, foreground emission, and instrumental effects like primary beams have been incorporated, hundreds of thousands of parameters are required to fully describe the model. Hydra uses a technique called Gibbs sampling to efficiently draw samples from the joint posterior distribution of all the parameters. It is implemented in Python and is compatible with the data formats used by the HERA pipeline, such as UVData and UVBeam. |
| Type Of Technology | Software |
| Year Produced | 2024 |
| Open Source License? | Yes |
| Impact | Hydra is still under development, but has been used in several publications. |
| URL | https://github.com/HydraRadio/Hydra |
| Description | Interview for Physics World |
| Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Media (as a channel to the public) |
| Results and Impact | I was interviewed by a journalist for Physics World for an in-depth article on our field, related to topics supported by the grant. There are no known impacts apart from generating wider awareness of our research area and informing the public and physics-specialists about it. |
| Year(s) Of Engagement Activity | 2025,2026 |
| URL | https://physicsworld.com/a/cosmic-dawn-the-search-for-the-primordial-hydrogen-signal/ |
| Description | Lovell Lecture at Jodrell Bank Observatory |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Public/other audiences |
| Results and Impact | This was a public lecture called "Chaos at Cosmic Dawn" on the topic of early Universe physics, at the Jodrell Bank Centre for Engagement. Around 200 people attended on the evening, with another approx. 100 watching online. |
| Year(s) Of Engagement Activity | 2025 |
| URL | https://www.jodrellbank.net/events/professor-phil-bull-chaos-at-cosmic-dawn/ |