Why Choose RF Energy for Automotive Ignition?

May. 09, 2018

automotive ignition.jpgPerhaps one of the most lucrative commercial applications available to solid-state radiofrequency (RF) energy is in the automotive industry, known for its dedication advancing vehicle technology with every model. Traditionally enabled by spark plugs, vehicles can now benefit from RF solid-state plasma technology, which offers improved fuel efficiency and reduced carbon footprint.

What is RF Energy?

The concept for RF energy powered ignitions dates back to 1992, following the 27th Intersociety Energy Conversion Engineering Conference in San Diego, California, where the idea of lean, precise automotive ignition without the use of the traditional spark plug was first introduced. Automakers grappling with increasingly stringent vehicle emissions protocol, allowing for only a small carbon footprint and facing potential fines for every car which omits over protocol, were in need of a seamless solution to improve efficiency without completely redesigning the engine. Solid-state RF energy presented an opportunity to offer an unprecedented level of control and efficiency to auto ignitions, thereby reducing waste and cost, with equivalent footprint. At the time, further analysis was required in order to control the physical volume of plasma created by the RF discharge.

Today, due to recent advancements enabled by organizations like the RF Energy Alliance, innovative new technologies such as MACOM’s GaN-on-Si displacing incumbent LDMOS and collaborations like STMicroelectronics and MACOM, RF energy is now poised to achieve the optimal performance, scale and cost structure to enable this formerly “futuristic” application. Fuel efficiency improvement has become a choice not only for car manufacturers, but for consumers to demand as standard.

Spark Plugs vs. RF Plasma Ignition

The concept of spark plugs are simple: deliver an electric current to a vehicle’s combustion chamber, emit a one-time electric spark—similar to that of a lightning bolt—to ignite the compressed fuel and air mixture, which then moves the pistons of the engine and voila. Due to the erratic, natural behavior of the initial spark, the technology is inconsistent in terms of duration per start and amount of gas expended per start. Generating a high voltage spark in combination with the timing it takes to start the “cranking” of an engine, any gasoline which lies in the ignition chamber is burned, even if gas levels are low or diluted. Though fractional in seconds, the use of unnecessary gas combinations accumulates. Despite these inefficiencies, many car manufacturers have stuck with spark plugs due to the familiar technology and low cost structure (previously unavailable with an RF plasma solution).

RF plasma, on the other hand, offers a constant array of energy. The constant energy source is beneficial to a vehicle, bringing higher combustion ratios, the ability to control and manipulate the plasma, and operate flawlessly under extreme pressure time and time again—whereas traditional spark plugs can only work to a certain pressure constraint, resulting in fuel mixtures which are sub-optimal.

By leveraging RF energy in lieu of a spark plug, fuel in the combustion chamber can be ignited much more evenly than with conventional ignition systems. The precision control afforded by RF plasma-powered ignitions can largely reduce exhaust emissions and save on fuel by using a plasma to accurately optimize the fuel combustion process. Aggregated globally, a 10% improvement in fuel efficiency for combustion-powered vehicles would represent a significant leap forward in carbon emissions control. 

Looking Forward

RF plasma ignitions not only have the potential to better serve the automotive industry, but can optimize performance in motor bikes, diesel trucks, large industrial engines and more. MACOM has recently started to develop an integrated circuit, the Analog Lock Loop, which is expected to provide a cost effective control loop for the solid state amplifier to deliver energy efficiently to the RF plasma ignition under the controlled environment. Following MACOM’s recently announced collaboration with STMicroelectronics to commercialize GaN-on-Si for RF markets, a plasma ignition could be in a low-end car market sooner than you think!


All financial guidance projections referenced in this post were made as of the publication date or another historical date noted herein, and any references to such projections herein are not intended to reaffirm them as of any later date. MACOM undertakes no obligation to update any forward-looking statement or projection at any future date. This post may include information and projections derived from third-party sources concerning addressable market size and growth rates and similar general economic or industry data. MACOM has not independently verified any information and projections from third party sources incorporated herein. This post may also contain market statistics and industry data that are subject to uncertainty and are not necessarily reflective of market conditions. Although MACOM believes that these statistics and data are reasonable, they have been derived from third party sources and have not been independently verified by MACOM.


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