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All Rights Reserved. info@cellencor.com (Cellencor, Inc.) support@globalreach.com (Global Reach Internet Productions) Tue, 10 Mar 2026 13:28:16 -0500 Tue, 10 Mar 2026 13:28:16 -0500 60 http://www.cellencor.com/index.cfm/86995-1/19078/solidstate_microwave_patents_awarded Wed, 30 Sep 2020 15:23:51 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/19078/solidstate_microwave_patents_awarded <p><img alt="" src="/documents/filelibrary/US20190080886A120190314D00002_710EBADADC13F.png" style="margin: 10px; float: right; width: 250px; height: 167px;" />Cellencor is happy to announce that our solid-state microwave generator patents were issued July, 21 2020.</p> <p><a href="https://patents.google.com/patent/US20190080886A1/en?assignee=cellencor&amp;oq=cellencor" target="_blank">Read the full patent here.</a></p> <p>&nbsp;</p> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/19077/new_dualband_test_oven Thu, 10 Sep 2020 14:19:43 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/19077/new_dualband_test_oven <h2><img alt="" src="/documents/filelibrary/SS_dual_band_batch_cavity_w_PP_scre_C7C9205AEE3C5.png" style="margin: 20px; float: right; width: 300px; height: 260px;" />Gap in the Market</h2> <p>One challenge often faced at Cellencor is the design and development of microwave test applicators for both customer-specific processes and general research and development. The power and flexibility offered by Cellencor&rsquo;s line of solid-state microwave generators opens up entirely new avenues of scientific exploration, but this can be hampered by the lack of a suitably sized test oven outfitted with the instrumentation and measurement systems required for proper microwave heating research. Current market solutions consist of either small home microwaves (~2ft³) designed only for use at 2450MHz, or excessively large microwave cavities (volume?) designed for industrial-scale processing various materials or food products at the 915MHz frequency band. This leaves an obvious market opening for mid-sized microwave cavities that can be used for microwave heating R&amp;D or small-scale batch production.</p> <h2>Dual-Band Microwave Test Oven</h2> <p>In order to meet both customer and market needs, Cellencor has designed a new <em>Dual-Band Microwave Test Oven</em> that is capable of operating at both the 2450MHz and 915MHz ISM bands. A top-fed WR975 waveguide port brings power into the cavity, with an adapter plate included to convert this to WR340 waveguide for use at 2450MHz. A 7/16 DIN barrel feed is also included on the back wall, allowing a coaxial line to be fed directly into the cavity for use with alternative antennas.&nbsp; A custom-designed front hatch is used to load and unload material from the cavity; an emergency stop latch was added to the front hatch, preventing the system from operating while the door is open. An emergency stop switch was also added to the front of the system. &nbsp;The system is outfitted with a series of sanitary tri-clamp fittings that serve as sensor ports, allowing IR temperature sensors, arc flash detection sensors, RTD temperature probes, cameras, moisture content analyzers, and other measurement devices to be used with the cavity during operation. Additional exterior shelving makes it possible for a PTS-1 or PTL-2.5 and all associated equipment to be mounted directly next to the cavity, reducing the length of any coaxial lines and effectively making this a stand-alone microwave research oven. Lastly, the oven was outfitted with an optional turntable to provide another method for evenly distributing the heating within the load, in addition to the frequency-sweeping capabilities of the Precise Power hardware.</p> <h2>Design and Engineering</h2> <p>The design process for this test oven began with COMSOL Multiphysics, which was used to determine the optimal cavity dimensions for sustaining resonance in both the S- and L-bands. Following this, the mechanical design and construction were straightforward. The completed oven is shown below, along with comparisons between the cavity return loss calculated by COMSOL and the cavity return loss as measured by Precise Power software when connected to the oven. A microwave leakage probe was used to test for any microwave leakage from the oven door seal and corner seams; the maximum reading taken was 1mW/cm²when 1kW of power at 2450MHz was applied to the cavity, indicating the cavity is extremely well-sealed and doesn&rsquo;t post any safety hazards with respect to microwave leakage.</p> <h2>Multipurpose Tool</h2> <p>This microwave oven will serve as a valuable research tool, allowing significantly more data to be collected on various heating and drying processes. This in turn will allow greater control over the heating/drying process and improve the quality of the final results. This makes it an ideal solution for customers who need to scale up beyond a benchtop system, but don&rsquo;t need a full-sized industrial oven designed for integration into a production system.</p> <h3><a href="/en/services/testing_options/microwave_test_facility/dual_band_microwave_test_oven/">Additional information on the test oven.</a></h3> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/18975/comsol_design_process Fri, 10 Jul 2020 12:37:59 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/18975/comsol_design_process <h2>Applicator Design</h2> <p>In addition to being leaders in the design of cutting-edge microwave technology, Cellencor is proud to offer microwave applicator design consulting. This includes the design of custom microwave heating applicators such as furnaces or resonant cavities, waveguide mode transitions, optimized antenna design/selection, and application feasibility studies. This is accomplished through the use of 3D CAD modelling and powerful electromagnetic wave simulation software.</p> <h2>Starting Point</h2> <p>The design process begins with the need to answer questions regarding the fundamental characteristics of a potential microwave applicator. Factors such as desired mass throughput, operating frequency, vacuum-sealed or gas-purged cavities, plasma generation application, and the load material&rsquo;s dielectric and thermal properties affect various design parameters such as recommended operating frequency, applicator size, antenna feed type, appropriate power level, and whether the system will be conveyor based, batch-style, or continuous-flow. This all informs the basic size and shape of the microwave applicator, as well as the approximate location of the antenna feed. The load material&rsquo;s physical properties and phase state, and desired output material, will also play a large role in determining the applicator geometry and type.</p> <h2>Simulation</h2> <p>Once the basic design aspects of the applicator like cavity size and antenna feed have been determined, and the relevant material properties identified, an RF heating simulation can be constructed using COMSOL Multiphysics. This simulation can be used to determine where electromagnetic hot/cold spots exist in a cavity and in the load material, estimate the temperature rise of the load, calculate the amount of power reflected back to the input port and the amount absorbed by the load, and identify and areas of microwave leakage in a cavity design. This feedback can then be used to adjust and optimize the cavity geometry in order to concentrate microwave energy at a desired location, determine the optimal location of the load material inside a cavity or applicator, compare the performance of different antennas for a specific heating application, and mitigate and leakage of microwave energy.</p> <h2>Mechanical Drawing</h2> <p>Once the electromagnetic design of a microwave cavity or heating applicator is completed, a complete mechanical design of the system is required. This may consist of integration into an existing production line or the development of a stand-alone microwave system. The use of heating simulations eliminates the need for costly prototypes and significantly reduces the time to reach production. Some example applications are shown below:</p> <p><img alt="" src="/documents/filelibrary/comsol_2_B06B9EE78AB88.jpg" style="margin: 10px; float: left; width: 250px; height: 153px;" /><img alt="" src="/documents/filelibrary/comsol_1_FAC8B9D003776.jpg" style="margin: 10px; float: left; width: 250px; height: 153px;" /></p> <h3>&nbsp;</h3> <h3>&nbsp;</h3> <h3>&nbsp;</h3> <h3>&nbsp;</h3> <h3><img alt="" src="/documents/filelibrary/comsol_3_77A5F2575D92E.jpg" style="margin: 10px; float: left; width: 250px; height: 153px;" /><img alt="" src="/documents/filelibrary/comsol_4_84B16F046F9CA.jpg" style="margin: 10px; width: 250px; height: 153px; float: left;" /></h3> <h3>&nbsp;</h3> <h3>&nbsp;</h3> <h3>&nbsp;</h3> <h3>&nbsp;</h3> <h3>&nbsp;</h3> <h3><a href="/en/services/design_and_engineering/simulation_and_modeling/" target="_blank">Additional Information about computer modeling. </a></h3> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/18962/microwave_myths_debunked Wed, 29 Apr 2020 14:31:24 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/18962/microwave_myths_debunked <h2><img alt="" src="/documents/filelibrary/myth_VS_fact_48513F125A371.png" style="margin: 0px 20px; float: right; width: 209px; height: 167px;" />True or False?</h2> <p>At Cellencor, we actively try to debunk microwave myths and misconceptions and educate our customers. We feel that microwaves are grossly underutilized in the industrial and scientific sector partly because they are often misunderstood.&nbsp; There are many uses of microwaves which either have not been fully explored or on a very limited basis.</p> <h2>Mysterious Magic Box</h2> <p><a href="https://www.bls.gov/cpi/quality-adjustment/microwave-ovens.htm" target="_blank">According to the US bureau of Labor and statistics, over 90% of households in the US have a microwave oven.</a> However, to most, this appliance remains a mysterious magic box. A majority of people have very limited knowledge about how microwave ovens actually work. Many people even have strong misconceptions about microwaves. Such as the phrase &lsquo;<em>nuking a potato&rsquo;</em>, this misnomer often implies to people that microwaves somehow use nuclear radiation or are radioactive. This is far from the truth, as microwaves are non-ionizing electromagnetic waves. &nbsp;Many people also learn half-truths, such as &ldquo;<em>do not put metal in a microwave</em>&rdquo;. In general this is true, but the damaging arcing associated with metal has more to do with the shape of the metal then the metal itself. Many modern food packages actually safely use metal in a microwave to help heat the food or increase convenience.&nbsp; A common example of this is crisping sleeves that come with Hot Pockets &trade; brand frozen sandwiches. &nbsp;They work by mixing metallic powder into the paper sleeves which converts the microwave energy into radiant heat, crisping the outside of the food while the microwaves cook the inside. This metallic material in this application is called a susceptor. Another instance of safe metal in a microwave is the microwave safe pull top bowls sold by Chef Boyardee&trade;. They have a metal rim that remains after the pull top has been removed. This pull top is a convenient feature as the meal can be made without needing to use a can opener.&nbsp; The metal rim goes into the microwave with no ill effects.</p> <h2>Misconceptions</h2> <p>Another basic misunderstanding that we often come across is that microwaves heat foods from the inside out. While there is indeed volumetric heating occurring you have to consider the scale. Microwaves will get absorbed as they pass through a material, so if the material is large enough or the microwaves are too weak or a high frequency it will not heat the core.&nbsp; We call this penetration depth. Practically speaking, volumetric heating is a big advantage of microwave heating.</p> <p>The majority of people who do have a basic understanding of how microwaves work will often remember what they were taught from their high school physics class, which usually gets shortened to; <em>&ldquo;the microwave causes water molecules to vibrate which causes heat&rdquo;.</em> This sentence is technically correct; however a lot of information is missing in this answer.</p> <h2>Microwaves are Radio Waves</h2> <p>Microwaves are radio waves, like the radio waves used in cell phones for communication just many magnitudes stronger. This basic understanding that microwaves cause water molecules to vibrate is also an oversimplification that causes many people to believe microwaves can only heat stuff that has water in it, that simply isn&rsquo;t true. All materials can react to microwave fields depending on the molecular structure of the material. When microwaves encounter a material, the waves can behave three different ways; they can be reflected, they can be absorbed, or they can be pass through or any combination of these. Some materials are completely invisible to microwaves and show practically no interaction such as HDPE, Polypropylene, PTFE (Teflon&trade;), fused quarts and more. The microwaves pass through the material and none of the energy is converted to heat. This can be extremely useful; our conveyor belts are often made from polypropylene! This allows us to carry materials through a microwave oven on industrial scales<a href="/index.cfm/86995/17460/how_green_are_microwave_drying_systems" target="_blank"> without wasting energy heating</a> the conveyor belt. Some materials reflect microwave energy and also show little interaction. Most sheets of metal reflect the majority of the microwaves and show little heating. This is also very useful as this allows us to contain the microwaves inside metal boxes to concentrate their effect and increase efficiency. Some materials, like water, easily convert the microwave energy to heat. However, the energy that gets absorbed can actually happen through four different mechanisms.</p> <h3>Dipole Rotation</h3> <p>This is the most common form of heating. This is how water molecules are heated in your home microwave. However, this mechanism can act on any polar molecule that is the correct shape. Alcohols are a good example of other polar molecules that heat in microwave fields.</p> <h3>Ionic Conduction&nbsp;</h3> <p>This mechanism of heating is less common but still frequent. This occurs when a material has disassociated ions. The free ions do not try to rotate with the microwave fields like dipole rotation instead they try to moved back and forth through the material as the waves pass by. One simple way you can see this phenomenon is by adding table salt to a glass of water and heating it in a microwave next to some distilled water. The water with the salt will have Na+ and Cl- ions in suspension. When the microwave field is applied these ions also react and the solution will heat faster than the water without the ions (the distilled water).</p> <h3>Resistive Heating</h3> <p>This mechanism of action is much less common and occurs when the microwave fields induce an electrical current passing through the material. This generally only happens in materials that are electrically conductive. In conductive powders such as carbon this can also cause micro arcs between each small particle. These micro arcs are converting large electrical voltages which jump from one particle to another and convert a lot of that energy ionizing the air into plasma!</p> <h3>Magnetic Hysteresis</h3> <p>This is the least common mechanism of action and is usually only seen when materials that have a magnetic field are exposed to microwaves. Magnetic fields can also induce electrical current in conductive materials called Eddy currents. These currents will contribute to resistive heating (mechanism 2). Ferrite is a good example of this mechanism. Ferrite is often used as noise chokes on electronics. Many electronics such as laptops will have a bump near the plug. This bump is a chunk of ferrite aimed at filtering out unwanted noise (radio waves). When the ferrite is exposed to microwave fields the magnetic fields resist the microwaves and convert some of this energy into heat. &nbsp;</p> <p>These four mechanisms are not fully understood for all materials and sometimes the best way to categorize how a particular material behaves in a microwave is by empirical testing. The field of microwave enhanced chemistry is also booming at the moment due to these phenomena and their poorly understood interaction with chemical reactions.</p> <p>Pictured below is a graph of many common materials and how well they heat in a microwave relative to water.&nbsp; This is not a comprehensive list, but it allows people to quickly get a sense of how well a particular material should heat in a microwave from dipole rotation. Materials on the left have poor coupling and materials on the right couple very well and heat quickly.<img alt="" src="/documents/filelibrary/Material_Heating_Comparison_DFEF30648E8E3.png" style="border-width: 1px; border-style: solid; margin: 30px 15px; width: 800px; height: 491px;" /></p> <p>We implore you to do your research and be an informed consumer; don&rsquo;t believe everything you read about microwaves out there, much of it is false. Cellencor will continue trying to debunk these and other myths.</p> <blockquote> <p><a href="/en/contact/" target="_blank"><em><strong>If you found this article helpful or have other questions about how microwaves can help you or your business please reach out to us today and we will gladly help get you pointed in the right direction!</strong></em></a></p> </blockquote> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/18938/worlds_first_large_scale_solid_state_industrial_microwave_system Wed, 05 Feb 2020 17:53:37 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/18938/worlds_first_large_scale_solid_state_industrial_microwave_system <p><span class="paragraph_text" style="border-style:none;color:#546070;font-family:roboto,sans-serif;font-size:1rem;line-height:1.5em;margin-bottom:0.75em;margin-top:0.25em;">Crescend Technologies along with Cellencor, Inc announces the delivery of a 400 kilowatt, solid state L-band power system to a customer site.&nbsp; It is believed to be the first large scale deployment of high power solid state RF power in the world.&nbsp; The application is processing large volumes of high value biomass products.</span></p> <h2>World&#39;s Largest</h2> <p><span class="paragraph_text" style="border-style:none;color:#546070;font-family:roboto,sans-serif;font-size:1rem;line-height:1.5em;margin-bottom:0.75em;margin-top:0.25em;">The overall system consists of eight PTL-50 solid state microwave generators, each providing 50 kilowatts of continuous RF power in the 902-928 MHz ISM band.&nbsp;&nbsp; The generators are paired to produce four 100 kilowatt waveguide feeds to the microwave applicator.&nbsp;&nbsp; This system also includes comprehensive software support for controlling the generators and interfacing to the user process.</span></p> <h2>System Control</h2> <p><span class="paragraph_text" style="border-style:none;color:#546070;font-family:roboto,sans-serif;font-size:1rem;line-height:1.5em;margin-bottom:0.75em;margin-top:0.25em;">Crescend&#39;s PTL-50 L-band microwave generator delivers 50 kilowatts of continuous or pulse width modulated power. Power control and measurement is accurate to better than 0.1%.&nbsp; The PTL-50 is supplied with the PrecisePower feature-rich Windows&trade;-based interactive control software suite which includes support for advanced features such as frequency sweeping, automatic tuning, load analysis, and built-in analytic tools to help scientists and engineers better manage the setup and operation of their microwave applications.&nbsp; External control options include Ethernet, LabView, and PLC compatible electrical interface.</span></p> <h2>Advantages</h2> <p><span class="paragraph_text" style="border-style:none;color:#546070;font-family:roboto,sans-serif;font-size:1rem;line-height:1.5em;margin-bottom:0.75em;margin-top:0.25em;">In the past, the only choice of high power RF for these types of applications has been magnetron-based microwave generators.&nbsp; Compared to magnetrons, solid state power provides many important new advantages, including radically higher reliability, lower operating costs, easier and safer maintenance, better energy efficiency, frequency agility, and automatic load matching.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span></p> <h2>Generator Portfolio &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</h2> <p><span class="paragraph_text" style="border-style:none;color:#546070;font-family:roboto,sans-serif;font-size:1rem;line-height:1.5em;margin-bottom:0.75em;margin-top:0.25em;">Crescend&rsquo;s Solid State Generator System portfolio includes models covering ISM bands of 2.4-2.5 GHz with 1 kilowatt to 12 kilowatts and 902-928 MHz with 3 to 100 kilowatts. &nbsp;Standard and customized configurations are available. &nbsp;All products are engineered and manufactured in Crescend&#39;s Schaumburg, Illinois USA facility.</span></p> <h2><strong><a href="/en/products/solid_state_generators/" target="_blank"><span class="paragraph_text" style="border-style:none;color:#546070;font-family:roboto,sans-serif;font-size:1rem;line-height:1.5em;margin-bottom:0.75em;margin-top:0.25em;">Additional Product&nbsp; Information</span></a></strong></h2> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/18652/electromagnetic_simulation_of_antenna_performance_solidstate_microwaves Tue, 18 Sep 2018 16:14:35 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/18652/electromagnetic_simulation_of_antenna_performance_solidstate_microwaves <p><strong>INTRODUCTION</strong></p> <p>The advent of high-power solid-state microwave technology makes possible the use of coaxial transmission lines and unconventional antenna configurations, something not previously possible when using magnetrons at ISM frequencies without expensive, lossy waveguide-to-coaxial adapters. With this in mind, computer simulations of microwave heating models can serve as valuable tools in the development and control of novel microwave heating processes, as well as the design of new microwave applicators [1]. It is widely accepted that using simulations to optimize applicator configuration can significantly reduce the time and cost associated with developing a new process, and this optimization includes determining which type of antenna is most appropriate for a given application [2]. For this study, the simulation includes a generic lossy load placed in a rectangular cavity that is designed for use at S-band frequencies, with 1kW of energy applied from one of three antenna types: a WR340 waveguide feed, a quarter-wave monopole antenna, and a half-wave dipole antenna. COMSOL Multiphysics was used to model the coupling between the electromagnetic and thermal physics.</p> <p><strong>VIRTUAL PROCESS OPTIMIZATION</strong></p> <p>Factors that affect the power density distribution and temperature profile of a microwave heating process include material sample size, sample location inside the applicator, operating frequency, applied power, applicator geometry, type of antenna used, and antenna orientation [3]. Controlling for these variables allows a direct comparison of how different antennas behave within the system. Parameters to consider when deciding which antenna is most appropriate for a given application include efficiency, heating uniformity in the load, power handling capabilities, antenna bandwidth, and cost. Antenna bandwidth is particularly important due to the frequency-agile nature of solid-state transmitters. By using computer simulations to analyze changes in the absorbed energy, power density distribution and heating profile across the frequency band, it is possible to determine the optimal configuration of the microwave applicator, including any frequencies within the operating band that should be avoided due high return loss.</p> <p>RESULTS</p> <p><img alt="" src="/documents/filelibrary/blog_post_photos/S11_waveguide_704A46CF790E5.jpg" style="width: 250px; height: 204px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/S11_monopole_521603379343D.jpg" style="width: 250px; height: 196px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/S11_dipole_5CB821D953D23.jpg" style="width: 250px; height: 196px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/AbsorbedPower_waveguide_CC4253926530A.jpg" style="width: 250px; height: 204px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/AbsorbedPower_monopole_78F1926E856E2.jpg" style="width: 250px; height: 196px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/AbsorbedPower_dipole_2C19C1FC7A1C7.jpg" style="width: 250px; height: 196px;" /></p> <p style="text-align: center;">Figure 1: TOP: Plot of S₁₁vs. Frequency for waveguide, monopole, and dipole feeds. BOTTOM: Plot of absorbed power vs. Frequency for waveguide, monopole, and dipole feeds.</p> <p align="center"><img alt="" src="/documents/filelibrary/blog_post_photos/IMPI_Abstract_Waveguide1jpg_7816A59D6BDA5.jpeg" style="width: 250px; height: 170px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/IMPI_Abstract_Monopole1_ED6889CCBE1D9.jpeg" style="width: 250px; height: 170px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/IMPI_Abstract_Dipole1_E52BAB616683F.jpeg" style="width: 250px; height: 170px;" /></p> <p align="center">Figure 2: Electromagnetic fields inside microwave cavities excited by (left to right) WR340 waveguide, 1/4&lambda; monopole antenna, and 1/4&lambda; dipole antenna. Results shown are at 2.450GHz.</p> <p align="center"><img alt="" src="/documents/filelibrary/blog_post_photos/IMPI_Abstract_Waveguide2_5A8B42E0F21E5.jpeg" style="width: 250px; height: 170px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/IMPI_Abstract_Monopole2_07849E0D7C1E7.jpeg" style="width: 250px; height: 170px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/IMPI_Abstract_Dipole2_1DCAC15F5B833.jpeg" style="width: 250px; height: 170px;" /></p> <p align="center"><img alt="" src="/documents/filelibrary/blog_post_photos/IMPI_Abstract_Waveguide3_07B37253AFB9E.jpeg" style="width: 250px; height: 170px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/IMPI_Abstract_Monopole3_32559EA0AD553.jpeg" style="width: 250px; height: 170px;" /><img alt="" src="/documents/filelibrary/blog_post_photos/IMPI_Abstract_Dipole3_6D16647AB913B.jpeg" style="width: 250px; height: 170px;" /></p> <p align="center">Figure 3: TOP: E-field distribution in cavity load for (left to right) WR340 waveguide, 1/4&lambda; monopole antenna, 1/4&lambda; dipole antenna. BOTTOM: Temperature distribution in cavity load for (left to right) WR340 waveguide, 1/4&lambda; monopole antenna, and 1/4&lambda; dipole antenna. Results shown are at 2.450GHz.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>Apart from the visual results for the EM field and the heating profile, other important factors to consider are the scattering matrix parameters and the amount of incident power absorbed by the load. Figure 1 shows these values plotted across the frequency band for each antenna being considered, while Figure 2 displays the E-field distribution inside the cavity for each antenna. Figure 3 offers a direct comparison of the E-field power density to the heating profile of the cavity load.</p> <p><strong>CONCLUSION</strong></p> <p>The graphs in Figure 1 show a clear correlation between the amount of power absorbed by the load and the amount of power reflected back to the input, as well as indicating the bandwidth of each antenna configuration. The plots of absorbed power vs. frequency show that the waveguide feed is capable of delivering a greater percentage of the incident power to the load across a wider frequency range than either coaxially-fed antenna, despite a larger amount of reflected power across the frequency band<strong>. </strong>Analysis of the power density and heating profile from different antennas reveals vastly different patterns for each, which follows intuitively from the understanding that each antenna produces a distinct radiation pattern inside the cavity. The heating profiles also reveal varying degrees of heating uniformity between the antennas. In order to facilitate a direct comparison between antennas, each was ranked on a 3-point relative scale with 3 being the highest score, shown below in Table 1:</p> <p align="center"><img alt="" src="/documents/filelibrary/blog_post_photos/results_table_B488A2704FAE1.png" style="width: 300px; height: 159px;" /></p> <p align="center">Table 1: Comparison chart of three methods of delivering microwave energy to applicator.</p> <p>For this sample application, a waveguide feed appears to be most appropriate, followed closely by the monopole antenna.</p> <p><strong>REFERENCES</strong></p> <ol> <li value="NaN">Yakovlev, Vadim V., <strong>Computer Modelling in the Development of Mechanisms of Control over Microwave Heating in Solid-State Energy Systems</strong>, <em>AMPERE Newsletter</em>, Issue 89, pp. 18-21, 7 July 2016</li> <li value="NaN">Bressan, F., et al., <strong>An Optimization Method for the Control of Efficiency in Two-Port Microwave Ovens</strong>, <em>Conf. On Computation of Electromagnetic Fields (COMPUMAG)</em>, July 2013, Budapest, Hungary.</li> <li value="NaN">Cordes, Brian G. &amp; Yakovlev, Vadim V., <strong>Computational Tools For Synthesis of a Microwave Heating Process Resulting in the Uniform Temperature Field, </strong><em>Proc. 11th AMPERE Conf. Microwave &amp; High Frequency Heating</em>, Oradea, Romania, 3-6 Sept. 2007</li> </ol> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/18128/the_advent_of_solid_state_microwave_generation Thu, 27 Jul 2017 19:45:29 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/18128/the_advent_of_solid_state_microwave_generation <p>We&rsquo;re extremely excited and proud to be the creators of the PrecisePower&trade; family, our industry&rsquo;s first fully solid state microwave power sources.&nbsp; This family of system covers both the 900 MHz and 2400 Mhz bands with power levels up to<img alt="" src="/documents/filelibrary/Precise_power_desktop__cabinet_7064CF6466D9D.jpeg" style="width: 300px; height: 149px; margin: 20px; border-width: 1px; border-style: solid; float: right;" /> 75 kilowatts.</p> <p>Until now, the heart of every microwave heating device, including your home microwave oven, is the magnetron tube.&nbsp; This specialized radio tube was invented in 1940 and has not fundamentally changed much since then, except for getting bigger and more powerful.&nbsp; While magnetrons are very efficient in converting electric power to microwave energy, they have many limitations.&nbsp; First is their limited lifetime, about 6000-8000 hours for 900 MHz tubes, and about 2000 hours for 2400 MHz tubes.&nbsp; The transistors used in our new solid state systems have a lifetime in excess of <em>30 years</em> &ndash; over 250,000 hours!&nbsp; This long life also results in much higher reliability and less downtime.</p> <p>Another crucial feature of solid state microwave generators is <em>frequency agility</em>.&nbsp; Magnetrons operate on a single fixed frequency, either 915 MHz or 2450 MHz.&nbsp; Solid state units can cover the entire government allocated ISM bands at 902-915 MHz and 2400-2500 MHz.&nbsp;&nbsp; This has two big benefits.&nbsp; First, most microwave applicators have hot and cold spots due to wave interaction.&nbsp; That&rsquo;s why home microwave ovens have turntables and industrial systems have rotating antenna to ensure even heating.&nbsp; It turns out that when the microwave frequency is varied the hot and cold spots move around without mechanical assistance; simpler and more effective.&nbsp; Second, for maximum power transfer from the generator to the load proper matching is important.&nbsp; Mismatched systems will result in energy being reflected back to the generator which is lost as heat.&nbsp; Very often, adjusting the generator frequency to a &ldquo;sweet spot&rdquo; will provide an excellent match without using a hardware tuner.</p> <p>Power control with magnetrons can be slow (for 915 MHz systems) and/or limited (for 2450 MHz systems).&nbsp; &nbsp;As reflected in their name, PrecisePower&trade; generators offer nearly instantaneous and extremely accurate (&lt;0.1%) power control.</p> <p>An interesting new PrecisePower&trade; capability is high speed pulsed mode operation.&nbsp;&nbsp; This means the microwave can be switched at a frequency of up to 10 KHz with a variable duty cycle.&nbsp; Some prior research suggests that pulsed modes may have significant benefits in certain drying, plasma generation, and other applications.&nbsp; This field is largely unexplored because it&rsquo;s nearly impossible to do with magnetrons.&nbsp; We expect that some of our users will make some interesting and important discoveries in this area.</p> <p>These features and many others are highly accessible and easy to use using a powerful interactive software suite.&nbsp; The system can be controlled by a Windows app running on a PC via a USB connection.&nbsp; The generators can also be controlled as a LabView device or using a PLC-type hardware interface.</p> <h3><a href="/en/products/solid_state_generators/" target="_blank">Additional Information</a></h3> <p>&nbsp;</p> <p>&nbsp;</p> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/17459/industrial_microwave_frequencies Wed, 20 Jul 2016 20:52:30 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/17459/industrial_microwave_frequencies <p>Most industrial microwaves operated in one of two unlicensed, government allocated radio bands called the Industrial, Scientific, and Medical (ISM) bands.&nbsp; The lower &ldquo;L&rdquo; band ranges from 902 to 928 MHz.&nbsp; In Europe and some other regions 896 MHz is used to avoid interference to the 900 MHz GSM cellular phone band.&nbsp; The upper &ldquo;S&rdquo; band ranges from 2400 to 2500 MHz.&nbsp; Consumer microwave ovens also use this band, as do many other unlicensed wireless devices such as WIFI.</p> <p>Most high power industrial microwaves (30 or more kilowatts of power) use the 900 MHz band because it is possible to efficiently generate high power levels at the lowest cost per watt.&nbsp;&nbsp; Because of its relatively longer wavelength is also penetrates about 3 times more deeply into materials (typically about 10&rdquo;) compared to S band.</p> <p>S band systems tend to be physically much smaller and have lower power levels (about 1 to 10 kilowatts per generator).&nbsp;&nbsp; As mentioned previously, the penetration depth is less, about 3&rdquo; for food products. Waveguide used to carry the energy from the generator to the applicator is much smaller and less expensive compared to L band.&nbsp; S-band Magnetron units of exactly 1 kilowatt are relatively inexpensive because the tubes are manufactured in astronomical volumes for consumer microwave ovens.&nbsp; At any power level above 1 kilowatt the magnetron tubes become much more expensive.</p> <p>&nbsp;</p> <p><img alt="Industrial Microwave Frequencies - Cellencor" class="mobile-friendly-image" src="/documents/filelibrary/frequency_band_63683D1A29E34.png" style="margin: 5px; width: 600px; height: 258px;" /></p> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/17457/are_industrial_microwaves_safe Fri, 06 May 2016 20:47:40 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/17457/are_industrial_microwaves_safe <p>Microwaves are a kind of high frequency radio wave.&nbsp; In fact, the frequencies are the same as used by many consumer devices including cellular phones, WIFI, Bluetooth, and many other wireless devices.&nbsp; Radio waves (RF) are a type of electromagnetic waves called non-ionizing radiation.&nbsp; Despite uninformed slang about &ldquo;nuking&rdquo; a sandwich in the microwave, it has absolutely nothing to do with radioactivity.&nbsp; There are no known health risks associated with low power radio waves. &nbsp;Regardless, the government sets specific standards for maximum microwave leakage.&nbsp; In the US, the OSHA limit is a maximum of 5 milliwatts per square centimeter.&nbsp; For comparison, your smartphone can transmit 200 times more power (1 watt) in the same frequency range.&nbsp; Still, it&rsquo;s not a good idea to heat parts of your body with microwaves.</p> <p>All of our microwave equipment uses completely sealed metallic enclosures to prevent unintentional microwave leakage.&nbsp; All doors use special RF absorbing gasket material to prevent leakage.&nbsp; All of our equipment has elaborate safety interlocks to make sure it can be operated if a door is open or there is any other unsafe condition.&nbsp; We offer low cost leakage tester and encourage our customers to make testing a routine preventative maintenance action.&nbsp;Cellencor can provide copies of US Government publication on this subject.</p> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/17456/why_do_microwaves_heat_things_so_quickly Fri, 04 Mar 2016 21:47:22 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/17456/why_do_microwaves_heat_things_so_quickly <p>Microwaves produce a phenomenon called <em>volumetric heating</em>.&nbsp; Simply stated, they heat the entire mass of an object uniformly.&nbsp; This is because the microwave penetrated deeply into the object instead of just acting on the surface.&nbsp; Volumetric heating is unique to microwaves; almost all other forms of heating are <em>conductive</em>, where heat is applied to the surface of an object and it must travel to the interior by conduction.&nbsp; It takes a lot more time for the heat to move from the surface to the inside.&nbsp; This also results in a temperature gradient, where the outside is considerably hotter than the inside.&nbsp; This is why some skill is needed to properly grill a steak.</p> <p><img alt="" src="/documents/filelibrary/Microwave_VS_Conductive_Heating_98E4CC6368158.jpeg" style="width: 474px; height: 300px;" /></p> <p>Temperature gradients are usually undesirable in industrial applications because they can result in a product with non-uniform dryness or overheated areas.&nbsp; How deeply do microwave penetrate?&nbsp; This depends on the microwave frequency and the characteristics of the material being heated.&nbsp;&nbsp; For 915 MHz systems the penetration depth is typically 10&rdquo;, for 2450 MHz systems it&rsquo;s about 3&rdquo;.</p> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/17458/how_hot_do_materials_get_in_a_microwave_system Thu, 04 Feb 2016 21:46:59 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/17458/how_hot_do_materials_get_in_a_microwave_system <p>Microwave heating is a very versatile technology that can be used in a wide range of applications, so this question must be answered with respect to categories of applications.</p> <p>Many industrial microwave systems are used to dry various organic and inorganic materials, or to defrost, cook, or pasteurize food products.&nbsp; This class of applications takes advantage of the fact that microwave heat water molecules much more strongly than most other substances.&nbsp;&nbsp; In general, this means that the material will not get hotter than the boiling point of water.&nbsp;&nbsp; If needed temperature sensors and controls can regulate the exact temperature.&nbsp; This is a good thing for many food products, as excessive temperatures can damage beneficial proteins, enzymes, and other nutrients.&nbsp; This means that microwave processed foods can have better nutritional profiles than convection heated products.</p> <p>In another class of applications there is little or no water present, so the amount of heating depends solely on the dielectric properties of the materials.&nbsp;&nbsp; An example is heating catalysts for chemical reactions to very high temperatures.&nbsp; &nbsp;In this scenario, the operating temperature can range into the hundreds or even thousands of degrees.</p> <p>And finally we have microwave induced gas plasmas which can reach many thousands of degrees C.&nbsp; Microwave plasma systems are widely used by the semiconductor industry for deposition systems.</p> Cellencor, Inc. http://www.cellencor.com/index.cfm/86995-1/17460/how_green_are_microwave_drying_systems Fri, 01 Jan 2016 21:46:35 +0000 Blog http://www.cellencor.com/index.cfm/86995-1/17460/how_green_are_microwave_drying_systems <p>Very few drying technologies can approach microwave systems for positive environmental impact.&nbsp; In fact, in most cases environmental permitting is not required.&nbsp; Let&rsquo;s consider the common types of possible emissions and examine how microwave system measure up.</p> <p><strong>Combustion Products</strong> such as NOx and COx:&nbsp;&nbsp; This is simple.&nbsp;&nbsp; There is no combustion in a microwave system so there are no combustion products.</p> <p><strong>Particulates</strong>:&nbsp; Most microwave dryers carry material peacefully through the oven on a conveyor belt.&nbsp; There is no agitation, blowing, circulation, or any other movement of the material, so there are virtually no particulates.</p> <p><strong>Volatile Organic Compounds (VOCs): </strong>&nbsp;This depends on the material being processed.&nbsp; If it does not contain VOCs, there is obviously no problem.&nbsp; If there is some quantity of VOCs, the drying temperature is almost always below their boiling point, so they are not evaporated.&nbsp;&nbsp; Most of the time microwave dryers are also odor-free.</p> <p>So what comes out of the exhaust?&nbsp; Almost 100% water vapor. &nbsp;If you really want to ultra-Green, just set up a wind turbine out back and you will have a zero CO2 impact processing system.</p> Cellencor, Inc.