[Case Study] Microwave Heating for Pest & Bacteria Eradication

South Korea, Anyang - February 7th, 2024 - RFHIC (KOSDAQ:A218410) 

Case Study Summary:

A national research institute, specializing in electronics and IT technologies, embarked on a research project funded by the government to develop an innovative solution for enhancing agricultural productivity. The primary goal was to address the issue of soil degradation caused by harmful pests and bacteria, such as nematodes, that infest soil after crop harvesting, rendering it unsuitable for continuous cultivation.

Discover how the institute replaced its traditional magnetron systems to harness the power of RFHIC's 15kW, 900-930MHz, GaN solid-state microwave generator (RIK0915K-40TG). This switch enabled them to create a dependable and precise microwave source, designed to specifically combat the detrimental pests and bacteria responsible for soil degradation and hindered crop growth. 

Customer:

Funded by the government our customer is a national research facility that conducts R&D on electronics & IT technologies.
Our customer has been developing and researching a unique microwave heating system that would eradicate harmful pests and bacteria within soils that inhibit crop growth. 

After crops are harvested from a piece of land, parasites such as nematodes and various bacteria often infest the piece of land, rendering it unviable for continuous cropping. To deal with this problem, farmers are often forced to use fertilizers that pollute the environment and agricultural fields, or temporarily halt cropping altogether. With microwaves, the nematodes and bacteria can be eradicated in an environmentally friendly matter, increasing agricultural productivity.

Nematodes often infest soil after continuous cropping.

Customer Pain Points:

In the initial phases of developing their microwave heating system, our customer relied on magnetrons as the key components for microwave generation. However, they encountered significant challenges during the system design process, which are outlined below:

1. Shallow penetration and non-uniform heating patterns

Magnetrons have inherent issues with providing a stable source of microwave power due to their poor ability to provide a stable frequency signal. Factors such as temperature fluctuations, wear and tear from prolonged use, and variations in power supply can cause unexpected shifts in their frequencies. Additionally, due to their fixed resonant structure, magnetrons provide limited control over both frequency and phase. Consequently, magnetrons fall short of delivering deep penetration and consistent heating patterns. 

In the case of our partner's initial microwave-heating system, the magnetrons failed to produce microwaves that were uniform and deep enough to penetrate the soil effectively. The required temperatures to eradicate nematodes and harmful bacteria are roughly 60 °C to 80 °C  respectively. The inability of magnetrons to penetrate the soil deep enough meant that certain parts of the soil often failed to reach these temperature points, and the targeted pests and bacteria were not removed effectively.

2. High Failure Rate Over Time

Magnetrons typically have short lifespans, lasting between 4,000 to 6,000 hours of operation. In addition to their limited lifespan, they operate at exceptionally high voltages, often reaching up to 20,000 volts. Due to these factors, users frequently find themselves in the position of having to replace malfunctioning magnetron units, as well as associated components like circulators, diodes, and launchers.

The need for frequent replacements not only escalates operational expenditures but also offsets the initial cost savings associated with procuring magnetrons at a lower upfront price.

Our partner's microwave heating systems were designed to operate on remote farmlands in rural areas. 
The potential failure of magnetron units in the heating system posed a challenge; the costs associated with transporting and replacing these units would be substantial, and the downtime during this replacement process would lead to increased operational expenses and diminished productivity.

RFHIC's Proposed Solution

RIK0915K-40TG was installed into our customer's microwave heating system.

RFHIC offered a 15kW, 900 - 930MHz GaN solid-state microwave generator, the RIK0915K-40TG, as an alternative to magnetrons. The RIK0915K-40TG is fabricated using RFHIC’s cutting-edge gallium-nitride (GaN) on silicon-carbide (SiC) technology. The RIK0915K-40TG comes fully equipped with a 3-phase, 4W 380VAC Wye configured power supply unit, a control module, and eight (8) solid-state power amplifier shelves.

Unlike magnetrons, RFHIC’s RIK0915K-40TG provides precise digital controlling capabilities through our provided Windows GUI. The provided window's GUI will allow the user to digital control and adjust the power, frequency, pulse, and phase to create the optimal recipe for their end product. With these features it allowed us to achieve a more uniform and deeper penetration depth, allowing them to effectively eliminate any harmful bacteria within the soil promptly. 

RFHIC's Windows GUI Software 

Moreover, the RIK0915K-40TG operates under much lower voltages (50V) and boasts an average lifetime of around 50,000 to 100,000 hours. 

RFHIC's microwave generator is thoughtfully designed with eight power amplifier shelves, each incorporating a redundancy feature to ensure a smooth and gradual decline in performance. In the event of a malfunction occurring in one or two shelves, the microwave generator will continue to function correctly until those shelves can be replaced. The generator is also equipped with hot-swappable power supply units which allows the users to replace any failed paks even while operating.

Key benefits

1. Consistent and Uniform Heating Patterns

915MHz, 30kW microwave heat distribution model.

RFHIC's state-of-the-art GaN solid-state microwave generator was able to produce uniform and consistent heating patterns, effectively penetrating the soil and heating the targeted area uniformly. This allowed the system to eradicate nematodes and harmful bacteria within the soil, leading to higher yields of crops and enhanced soil quality. 

2. Increased System Lifetimes and Stability.

Approximate Lifetimes of GaN Solid-State vs Magnetrons

RFHIC's GaN solid-state microwave generator had significantly longer lifetimes than magnetrons and proved to be stable due to its low voltage operations. In addition, the built-in redundancy feature, which allows the microwave generator to continue operating in case one of the power amplifier shelves fails, provided considerable flexibility and reliability in both system design and operation. 

For more information about our GaN solid-state microwave generator technology, please contact us here.

About RFHIC:

RFHIC (KOSDAQ: A218410) is a global leader in designing and manufacturing GaN RF & Microwave components and systems for applications in wireless communications, defense and aerospace, and RF Energy (Industrial, Scientific, and Medical) segments. We provide industry-leading solutions for gallium-nitride (GaN) transistors, high-power solid-state power amplifiers, and high-power microwave generator systems, all within our in-house production facility. We enlighten industries with RF and Microwave advancements. To expedite a future enhanced by technological innovation - to create a better connected, safer, and stronger world for generations. Learn more at www.c0006.bizhomepass.kr.

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Media Contact:

• Grace Cho
• RFHIC Corporation
• Manager, Global Sales & Marketing
• marketing@c0006.bizhomepass.kr