Skip to main content

Plasma Antenna Technologies

Periodic Reporting for period 2 - PATH (Plasma Antenna Technologies)

Reporting period: 2019-01-01 to 2022-03-31

High density plasma sources find a large number of industrial applications from material treatment to telecommunications. Overcoming the plasma density limit of a current source will open new frontiers in several technological fields.
PATH aimed at cross linking different competences to study and develop prototypes of plasma sources and plasma antennas based on radiofrequency (RF), direct current (DC) Hollow cathode, and hybrid technologies to be applied in gaseous plasma antennas (GPAs). A GPA is a plasma discharge confined in a dielectric tube that uses partially or fully ionized gas to generate and receive electromagnetic waves; GPAs are virtually “transparent” above the plasma frequency and become “invisible” when turned off. Unlike ordinary metallic antennas, GPAs and plasma antenna arrays can be reconfigured electrically (rather than mechanically) with respect to impedance, frequency, bandwidth, and directivity on time scales in the order of microseconds or milliseconds. It is also possible to stack arrays of GPAs designed to operate at different frequencies, as the mutual coupling between different GPA can be greatly reduced with respect to the one of conventional antennas.
During the project, an ultra-high frequency (UHF) dipole based on RF plasma technology has been developed and tested. The performance of this radiating element has been investigated via numerical analysis and tests and compared with a conventional dipole. A small array of plasma dipoles was numerically simulated to demonstrate that the mutual coupling between such elements is better than the one exhibited by conventional antenna arrays. This would suggest that this novel technology should improve the antenna system performance when flexibility and reconfigurability are the driving requirements.
This new technology of antennas based on plasma is well suited to applications in intelligent antenna systems, where ad hoc algorithms can exploit the capabilities of plasma antennas to tailor to the user needs within certain limits with sensible cost savings.
As a whole, the activities the project produced a wealth of scientific results generally in line with the expectations reported in the preliminary planning.
The project started with a comprehensive physical model of plasma-electromagnetic interaction and experimental activities carried out with two different type of plasma sources:
• Radio frequency (RF) source:, compact in design, cheap and easy to handle;
• Hollow cathode (HC) source:, higher density achievable, and high lifetime;
• Hybrid source testing: although just started, a stable discharge is achieved with the use of an innovative design combining advanced from RF and HC setups.
All the experimental tests and designs have been accompanied by state-of-the-art computational models. The plasma fluid model has been updated to obtain a numerical tool which aims at the solution of the equilibrium conditions of plasma sources.
In parallel to plasma related studies, the design of the antenna prototype and antenna simulations have been carried out. A plasma antenna analysis and trade-off has been carried out describing foreseeable advantages and way of exploiting the different discharges (RF and HC).
Two prototypes have been numerically simulated and developed: a plasma monopole based on HC (Hollow Cathode) and a plasma dipole based on RF (Radio Frequency) plasma sources. The preliminary results were compared and discussed and the RF source has been finally selected for the next step, thus being used to manufacture a plasma dipole.
The experimental results have been used to calibrate the simulation software. Both experimental results and antenna simulations showed that plasma antennas, when active, behave much like the metallic ones. The most notable difference when comparing active plasma antenna elements with metallic ones comes to the gain, which is lower for the plasma case, being plasma a lossy medium. By further increasing the plasma density, the performance of the plasma dipole is expected to increase. On the other hand, when the antenna elements are inactive, plasma antenna elements have the promising property of not distorting the active e-field of nearby antenna elements.
This property simplifies the antenna selection problem in plasma antenna arrays. In fact, antenna selection can be performed safely without taking into account any mutual-coupling details. This is not true for metallic antenna arrays, since the presence of additional inactive metallic antenna elements will distort the active e-field.
Four summer schools have been held, respectively in Southampton (UK), Padua (IT), Shanghai (CN), and Chania/Thessaloniki (GR)..
The Final Conference was held in Monte Porzio Catone (Frascati, Italy) partially in presence and partially in remote, and the results were presented to a relevant number of stakeholders, including leading aerospace industries.
Up to now, several technological strategies have been pursued to achieve plasma sources that can be either power efficient or reconfigurable or portable or high-density or small (with dimensions down to microns) or, finally, with extended lifetime; unfortunately, each strategy allows for just a few of the above-mentioned goals. PATH lays the foundation of a new line of technology, i.e. the design and fabrication of a plasma source that pushes the limit of Hollow cathode discharges and radio frequency sources as a breakthrough in the field. To tackle the drawbacks that come from each distinct plasma source, plasma physics, plasma technology, electromagnetics, and material manufacturing experts combined and are combining their expertise to advance science and technology for innovative navigation and telecommunication antenna systems.
The specific technological breakthrough, ensuring reliability at high frequencies and fast tunability rates, is of paramount importance to address the requirements of the future information society, especially in the areas of security and safety and in critical applications. Therefore, we expect this technology to have a huge social and economic impact, as it will affect many application fields, such as telecommunications and navigation (compact antennas and EM shields, multi-/narrow-/broad-band, reconfigurable, electronically steerable, jamming resistant), information and communication technologies (antennas embedded in internal/external surface of buildings, cars, aircrafts, mobile phones or wearable tissues open new horizons allowing high data rate interlink communication between users), aerospace, aviation and ground transportation, consumer electronics and health, driven by a major innovation in the physical layer of the future RF, microwave, and mm-wave systems. Potential barriers may be expected in the industrial costs for high rate mass market production that may limit the use of this technology to high level professional and safety critical applications.
Apart from the specific telecommunications sector, progress of plasma sources beyond the state of art will impact a larger field as plasma sources are used in many different fields from industry to space.
Attendees at the final conference
RF set-up in anechoic chamber
Final Conference Flyer - March 2022 - Monte Porzio Catone (Rm), Italy
Prototype plasma dipole
RF Source set-up in anchoic chamber in Thessaloniki
A moment of the Final Conference
plasma elements (RF)
RF Source electrical set-up in anechoic chamber
RF Source during final test in Anechoic Chamber
RF set-up in "schield" configuration
Hollow catod set-up (DC) plasma source