2018 – OUTLOOK

In 2018, MWI AG will conduct an extensive testing program.  Fuel efficiency and pollutant data will be determined for all liquid fuels (including synthetic fuels). Moreover, all significant statements from MWI AG will be verified by external testing agencies.

Other technical objectives of MWI AG include miniaturizing the microwave unit and optimizing energy consumption. The plans also call for installing the MWI technology in test vehicles.


MWI AG operates a two cylinder engine of the latest engine generation on a specifically developed engine test stand. The objective of the test stand is to have a direct comparison with leading-edge engine concepts, while demonstrating fuel efficiency gains and pollutant reductions.

A Siemens electrical motor runs the combustion engine as a slave until the combustion engine operates on its own. The same electrical motor then applies a load on the combustion engine (generator principle) to bring it to the adjusted test parameters. One of the two cylinders is in this case operated with the original spark ignition, while the other is operated with the MWI microwave ignition. The temperatures and lambda values are measured on each of the two exhaust manifolds. The original engine control unit is used to operate the cylinder with the spark ignition, while operating parameters are specifically generated for the cylinder with microwave ignition. The objective in this case is to control and measure the leaning out and injection timing of the fuel.

The two pressure increase curves in the figure shown here are intended to illustrate that microwave ignition releases significantly more effective output while injecting the same quantity of fuel per cylinder, as compared to conventional spark injection. As a function of the particular parameter settings, the pressure increase curve is steeper for microwave chamber combustion than for spark ignition. This means that the MWI combustion is faster and therefore more efficient. The yellow curves show higher maximum pressures, while their surface area integral illustrates that the total output is higher than under the blue curve.  At the same time, the microwave-based combustion in Cylinder 1 is cooler than in the comparative Cylinder 2 with spark ignition.

The demonstrated output increase of the engine is explained by the “cooler and faster combustion”.

The power increase generated by microwave ignition is likely to be of interest in motorsports.

MWI AG is currently predominantly focused on fuel and pollutant reduction. This objective is achieved by leaning out – or more specifically by injecting a reduced fuel quantity per operating stroke. The injected volumes can be very accurately adjusted separately for each cylinder.

The MWI chamber ignition method is already today able to meet the EU standards for 2021 through 2030!


Based on the experience gained with the microwave coupler and impedance adjustments on the flow chamber, important adjustment parameters could be transferred to the single cylinder diesel engine (Hatz ID-41). In order to prevent the self-ignition generated by the underlying engine design, the displacement was increased by increasing the bore and thus reducing the compression temperature. It was also necessary to retrofit a threaded bore to the interior of the combustion cavity in order to route microwave energy into the combustion cavity with the MWI microwave coupler. Due to space constraints, the injector needed to be removed and fuel needed to be fed to the combustion cavity with an intake tube injection.

MWI decided to use the Hatz diesel engine as the first trial engine since it is a rugged construction and is able to much more readily absorb misfires than an Otto engine. The disadvantage of modifying the engine was that fuel efficiency measurements and pollutant measurements were for the most part not possible.

By operating the first engine with a microwave ignition, valuable know-how was gained that was transferable to a two cylinder mass-produced engine for the next development step. This test series showed that MWI has the capability to reliably ignite an engine with externally supplied microwave energy. We were also able to demonstrate that it is possible to operate an all-fuel engine with various fuels (diesel, gasoline).

2014 to 2016 – FLOWS TEST STAND

The flow test stand gives MWI the ability to simulate an engine and to initiate microwave-based ignitions and combustions.

The combustions can be captured optically through a hole piston. The combustion chamber of the flow test stand is essentially identical with the combustion chamber of the current trial engine, which is operated on the engine test stand in parallel.

MWI uses the flow test stand to run ignitions and combustions at atmospheric pressure. For now, we were able to reliably ignite the test stand with gasoline, diesel, and kerosene.

The test stand can be used to reliably evaluate the ability to ignite fuels and their use in the trial engine.


Pilot project to assess the potential of MWI – microwave ignition with project sponsorship by the Deutsche Bundesstiftung Umwelt (DBU) [German Federal Environmental Foundation]. This project cleared the path for the next important step – developing a flow test stand. The idea for microwave ignition could not have been brought to the next development step without support from DBU.

2009 to 2010 – FIRST TEST STAND

With limited resources and assistance from dedicated partners, MWI built the first test stand to have the ability to conduct initial technical trials and measurements. This test stand was used to demonstrate for the first time that microwave ignitions are technically possible. The system was not yet able to generate stable, reproducible ignitions.


In 2006, MWI AG was awarded second place of the Cyber One competition, thereby laying the cornerstone for the technology development.

Award ceremony CyberOne 2006 Rudolf Leidig (bwcon), Armin Gallatz (MWI), Prof. Dr. Nikita Hirsch (MWI) Prof. Dr. Hans-Jörg Bullinger (President of Fraunhofer Corporation, ret.)