{"id":21436,"date":"2026-05-01T19:30:14","date_gmt":"2026-05-01T19:30:14","guid":{"rendered":"https:\/\/antennasimulator.com\/?p=21436"},"modified":"2026-05-01T19:30:15","modified_gmt":"2026-05-01T19:30:15","slug":"am-broadcasting-renaissance-modeling-the-next-generation-of-urban-signal-boosters-with-an-sof","status":"publish","type":"post","link":"https:\/\/antennasimulator.com\/index.php\/2026\/05\/01\/am-broadcasting-renaissance-modeling-the-next-generation-of-urban-signal-boosters-with-an-sof\/","title":{"rendered":"AM Broadcasting Renaissance: Modeling the Next Generation of Urban Signal Boosters with AN-SOF"},"content":{"rendered":"\n<p>The AM broadcasting landscape is on the verge of a major technological evolution. In the United States, the National Association of Broadcasters (NAB) has launched a regulatory and technical roadmap aimed at authorizing on-frequency signal boosters for the AM band. This initiative, led by David Layer, VP of Advanced Engineering at NAB, aims to leverage 2026 technology to deploy single-frequency networks that address coverage gaps in urban areas.<\/p>\n\n\n\n<p>As the industry moves toward submitting a formal case to the FCC by 2027, the focus for RF engineers has shifted to overcoming the rising electrical noise floor and transmitter site relocation (<strong>Fig. 1<\/strong>). For these new signal boosters to be effective, precision in near-field modeling and ground-system efficiency is paramount.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"466\" src=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig1-RadiatingTowers-1024x466.png\" alt=\"\" class=\"wp-image-12198\" srcset=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig1-RadiatingTowers-1024x466.png 1024w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig1-RadiatingTowers-300x136.png 300w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig1-RadiatingTowers-768x349.png 768w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig1-RadiatingTowers.png 1365w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\"><em><strong>Fig. 1:<\/strong> Radiating towers (or radio masts) used in various broadcasting applications. Images licensed under Creative Commons.<\/em><\/figcaption><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. Beyond Legacy Solvers: The James R. Wait Ground Model<\/h4>\n\n\n\n<p id=\"p-rc_c0976c1dae507cb4-103\">Standard electromagnetic solvers often fail to provide the accuracy required for low-frequency (LF) and medium-frequency (MF) broadcast engineering<sup><\/sup>. Most legacy tools, such as NEC-4 or NEC-5, rely on the Reflection Coefficient Method (RCM), which cannot account for physical ground resistance at the feed point<sup><\/sup>.<\/p>\n\n\n\n<p id=\"p-rc_c0976c1dae507cb4-104\">AN-SOF provides a definitive technical advantage through the exclusive implementation of the <strong>James R. Wait<\/strong> ground model (<strong>Fig. 2<\/strong>). This model allows for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Direct Wire-to-Ground Connections:<\/strong> Radials can be electrically bonded to the ground plane, a feature critical for modeling shunt-fed towers and grounded structures.<\/li>\n\n\n\n<li><strong>Realistic Impedance Calculations:<\/strong> Unlike NEC, which approximates monopoles over a screen as if they were over a Perfect Electric Conductor (PEC), AN-SOF calculates the true input impedance by accounting for physical ground resistance.<\/li>\n\n\n\n<li><strong>Power Accuracy:<\/strong> By modeling the transition from high-conductivity radial zones to lossy soil, engineers can accurately predict the transmitter power required to meet regulatory field strength requirements.<\/li>\n<\/ul>\n\n\n\n<p>For a deeper technical dive into these comparisons, refer to: <\/p>\n\n\n\n<p class=\"has-medium-font-size\"><strong><a href=\"https:\/\/antennasimulator.com\/index.php\/knowledge-base\/an-sof-implements-james-r-wait-theory-for-ground-losses-of-lf-mf-radio-masts\/\" target=\"_blank\" rel=\"noopener\" title=\"\">Beyond NEC: Accurate LF\/MF Grounding with the James R. Wait Model<\/a><\/strong><\/p>\n\n\n\n<p><\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1290\" height=\"689\" src=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2023\/06\/Broadcast_Tower_Radials_E-field.png\" alt=\"Monopole antenna model with ground screen showing E-field variation as distance changes.\" class=\"wp-image-6694\" srcset=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2023\/06\/Broadcast_Tower_Radials_E-field.png 1290w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2023\/06\/Broadcast_Tower_Radials_E-field-300x160.png 300w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2023\/06\/Broadcast_Tower_Radials_E-field-1024x547.png 1024w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2023\/06\/Broadcast_Tower_Radials_E-field-768x410.png 768w\" sizes=\"auto, (max-width: 1290px) 100vw, 1290px\" \/><figcaption class=\"wp-element-caption\"><em><strong>Fig. 2:<\/strong>\u00a0AN-SOF model of a broadcast tower with a radial ground system, showing the 3D radiation pattern and the E-field strength as a function of distance at 1 kW input power.<\/em><\/figcaption><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<h4 class=\"wp-block-heading\">2. Optimizing Compact Urban Boosters with Top-Loading<\/h4>\n\n\n\n<p id=\"p-rc_c0976c1dae507cb4-108\">Urban signal boosters are often restricted by zoning laws and limited physical footprints. Traditional quarter-wave towers may be impractical, making compact, top-loaded monopoles the preferred solution (<strong>Fig. 3<\/strong>).<\/p>\n\n\n\n<p id=\"p-rc_c0976c1dae507cb4-109\">Top-loading effectively increases the electrical height of a physically short antenna, which is essential for maximizing radiation resistance<sup><\/sup>. AN-SOF enables the simulation of various high-efficiency configurations, including:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Inverted-L and T Antennas:<\/strong> Simple, effective designs for restricted spaces.<\/li>\n\n\n\n<li><strong>X and Star Antennas:<\/strong> Symmetrical designs that utilize multiple radial top wires to achieve resonance and increase radiation efficiency.<\/li>\n\n\n\n<li><strong>Resonance Tuning:<\/strong> Engineers can optimize the length of horizontal elements to cancel the imaginary component of input impedance, dramatically improving efficiency compared to unloaded short monopoles.<\/li>\n<\/ul>\n\n\n\n<p>Detailed modeling guidelines for these structures can be found in:<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><strong><a href=\"https:\/\/antennasimulator.com\/index.php\/knowledge-base\/top-loaded-short-monopole\/\" target=\"_blank\" rel=\"noopener\" title=\"\">Design and Simulation of Short Top-Loaded Monopole Antennas for LF and MF Bands<\/a><\/strong><\/p>\n\n\n\n<p><\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1221\" height=\"733\" src=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/AN-SOF_Top-LoadedShortMonopole_Types.png\" alt=\"\" class=\"wp-image-13481\" srcset=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/AN-SOF_Top-LoadedShortMonopole_Types.png 1221w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/AN-SOF_Top-LoadedShortMonopole_Types-300x180.png 300w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/AN-SOF_Top-LoadedShortMonopole_Types-1024x615.png 1024w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/AN-SOF_Top-LoadedShortMonopole_Types-768x461.png 768w\" sizes=\"auto, (max-width: 1221px) 100vw, 1221px\" \/><figcaption class=\"wp-element-caption\"><em><strong>Fig. 3: <\/strong>Common configurations of top-loaded monopole antennas.<\/em><\/figcaption><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<h4 class=\"wp-block-heading\">3. Precision Contour Mapping for FCC Compliance<\/h4>\n\n\n\n<p id=\"p-rc_c0976c1dae507cb4-113\">The NAB initiative highlights the importance of the population residing between the 25 mV\/m and 2 mV\/m signal contours<sup><\/sup>. Mapping these thresholds in a lossy urban environment requires advanced surface wave analysis<sup><\/sup>.<\/p>\n\n\n\n<p>Using AN-SOF\u2019s specialized near-field tools, engineers can map exact coverage zones:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Multi-Coordinate Analysis:<\/strong> Utilize <strong><a href=\"https:\/\/antennasimulator.com\/index.php\/knowledge-base\/near-field-parameters\/\" target=\"_blank\" rel=\"noopener\" title=\"\">Cartesian, Cylindrical, or Spherical coordinate systems<\/a><\/strong> to vary the radial distance from the base and predict field strength at ground level.<\/li>\n\n\n\n<li><strong>Ground Wave Attenuation:<\/strong> By comparing the theoretical unattenuated case over PEC ground against the actual lossy ground conditions calculated via Wait&#8217;s theory, designers can visualize exactly where the signal drops below the 2 mV\/m threshold.<\/li>\n\n\n\n<li><strong>Simplified vs. Detailed Modeling:<\/strong> For rapid frequency sweeps or large-scale network planning, AN-SOF allows for simplified tower models that maintain the same radiation pattern and impedance accuracy as detailed structural models (<strong>Fig. 4<\/strong>).<\/li>\n<\/ul>\n\n\n\n<p>To learn more about efficient tower simulation techniques, refer to: <\/p>\n\n\n\n<p class=\"has-medium-font-size\"><strong><a href=\"https:\/\/antennasimulator.com\/index.php\/knowledge-base\/on-the-modeling-of-radio-masts\/\" target=\"_blank\" rel=\"noopener\" title=\"\">An Efficient Approach to Simulating Radiating Towers for Broadcasting Applications<\/a><\/strong><\/p>\n\n\n\n<p><\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1332\" height=\"705\" src=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig5-DetailedvsSimplifiedTowerModels.png\" alt=\"\" class=\"wp-image-12202\" srcset=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig5-DetailedvsSimplifiedTowerModels.png 1332w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig5-DetailedvsSimplifiedTowerModels-300x159.png 300w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig5-DetailedvsSimplifiedTowerModels-1024x542.png 1024w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2022\/10\/Fig5-DetailedvsSimplifiedTowerModels-768x406.png 768w\" sizes=\"auto, (max-width: 1332px) 100vw, 1332px\" \/><figcaption class=\"wp-element-caption\"><em><strong>Fig. 4:<\/strong> Comparison of detailed and simplified models of a quarter-wave radiating tower. The input impedance remains nearly identical, with 593 segments in the detailed model and 29 segments in the simplified model.<\/em><\/figcaption><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Technical Note:<\/h4>\n\n\n\n<p>As the industry transitions toward software-defined vehicle radios and enhanced signal-processing algorithms in 2026, the initial transmission infrastructure must be modeled with the highest possible fidelity to ensure noise reduction and audio clarity. AN-SOF provides the necessary computational electromagnetics (CEM) toolkit to meet these modern broadcasting challenges.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-dots\"\/>\n\n\n\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div style=\"height:5px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n<div class=\"wp-block-image is-style-rounded\">\n<figure class=\"alignleft size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"772\" src=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2025\/03\/TonyGolden.jpg\" alt=\"\" class=\"wp-image-12956\" style=\"width:95px\" srcset=\"https:\/\/antennasimulator.com\/wp-content\/uploads\/2025\/03\/TonyGolden.jpg 800w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2025\/03\/TonyGolden-300x290.jpg 300w, https:\/\/antennasimulator.com\/wp-content\/uploads\/2025\/03\/TonyGolden-768x741.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/figure>\n<\/div>\n\n<div style=\"font-size:24px;\" class=\"has-text-align-left wp-block-post-author has-text-color has-black-color\"><div class=\"wp-block-post-author__content\"><p class=\"wp-block-post-author__byline\">About the Author<\/p><p class=\"wp-block-post-author__name\">Tony Golden<\/p><\/div><\/div>\n\n\n<div style=\"height:7px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n<div style=\"font-size:15px;\" class=\"wp-block-post-author-biography\">RF ENGINEER &amp; PHYSICS PH.D. With 25+ years in Computational Electromagnetics, I\u2019m a passionate researcher focused on antenna modeling and design. As Founder of Golden Engineering LLC, I develop accessible, high-performance simulation tools that help RF engineers optimize their designs, educators teach complex concepts, and hobbyists bring antenna projects to life.<\/div>\n\n\n<div style=\"height:15px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p>Have a question?<\/p>\n\n\n\n<p>\ud83d\udcac <strong><a href=\"https:\/\/tawk.to\/tonygolden\" target=\"_blank\" rel=\"noreferrer noopener\">Ask me<\/a><\/strong> | \ud83d\udce7 <strong><a href=\"mailto:tony@antennasimulator.com\" target=\"_blank\" rel=\"noreferrer noopener\">Email me<\/a><\/strong> | \ud83c\udf10 <strong><a href=\"https:\/\/www.linkedin.com\/comm\/mynetwork\/discovery-see-all?usecase=PEOPLE_FOLLOWS&amp;followMember=tonygoldenansof\" target=\"_blank\" rel=\"noreferrer noopener\">Follow me<\/a><\/strong><\/p>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>The AM broadcasting landscape is on the verge of a major technological evolution. In the United States, the National Association of Broadcasters (NAB) has launched a regulatory and technical roadmap aimed at authorizing on-frequency signal boosters for the AM band. This initiative, led by David Layer, VP of Advanced Engineering at NAB, aims to leverage [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-21436","post","type-post","status-publish","format-standard","hentry","category-news"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/posts\/21436","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/comments?post=21436"}],"version-history":[{"count":13,"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/posts\/21436\/revisions"}],"predecessor-version":[{"id":21449,"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/posts\/21436\/revisions\/21449"}],"wp:attachment":[{"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/media?parent=21436"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/categories?post=21436"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/antennasimulator.com\/index.php\/wp-json\/wp\/v2\/tags?post=21436"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}