{"id":84563,"date":"2026-06-23T15:23:00","date_gmt":"2026-06-23T13:23:00","guid":{"rendered":"https:\/\/fhi.nl\/nieuws\/keysight-ap4021a-fs1-frequency-synthesizer-delivers-low-phase-noise-and-ultra-fast-frequency-switching-up-to-40-ghz\/"},"modified":"2026-06-23T15:28:20","modified_gmt":"2026-06-23T13:28:20","slug":"keysight-ap4021a-fs1-frequency-synthesizer-delivers-low-phase-noise-and-ultra-fast-frequency-switching-up-to-40-ghz","status":"publish","type":"news","link":"https:\/\/fhi.nl\/en\/news\/keysight-ap4021a-fs1-frequency-synthesizer-delivers-low-phase-noise-and-ultra-fast-frequency-switching-up-to-40-ghz\/","title":{"rendered":"Keysight AP4021A FS1 Frequency Synthesizer Delivers Low Phase Noise and Ultra-Fast Frequency Switching up to 40 GHz"},"content":{"rendered":"<header id=\"header\" class=\"header header--high header--branch\">\n\n\t\t\t\t\t\t\t\t\t\t<div class=\"header__background header__background--high\">\n\t\t\t\t\t<img decoding=\"async\" class=\"header__background-image\" src=\"https:\/\/fhi.nl\/app\/uploads\/2026\/06\/Keysight-AP4021A_touch-front.jpeg\" alt=\"\">\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\n\t\n\t<div class=\"container\">\n\t\t<div class=\"header__content\">\n\t\t\t<div class=\"header__first\">\n\n\t\t\t\t\n\t\t\t\t\n\t\t\t\t\n\t\t\t\t<h1 class=\"header__title\" >\n\t\t\t\t\tKeysight AP4021A FS1 Frequency Synthesizer Delivers Low Phase Noise and Ultra-Fast Frequency Switching up to 40 GHz\t\t\t\t<\/h1>\n\n\t\t\t\t<div class=\"header__dots-line\">\n\t\t\t\t\t<svg width=\"431\" height=\"9\" viewbox=\"0 0 431 9\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M430.799 4.192a1.136 1.136 0 1 1-2.272-.001 1.136 1.136 0 0 1 2.272 0Zm-27.272 0a1.135 1.135 0 1 1-2.27 0 1.135 1.135 0 0 1 2.27 0Zm-27.27 0a1.136 1.136 0 1 1-2.272-.001 1.136 1.136 0 0 1 2.272 0Zm-27.272 0a1.39 1.39 0 1 1-2.78 0 1.39 1.39 0 0 1 2.78 0Zm-27.78 0a1.645 1.645 0 1 1-3.29 0 1.645 1.645 0 0 1 3.29 0Zm-28.29 0a1.9 1.9 0 1 1-3.799 0 1.9 1.9 0 0 1 3.799 0Zm-28.799 0a2.154 2.154 0 1 1-4.308 0 2.154 2.154 0 0 1 4.308 0Zm-29.308 0a2.41 2.41 0 1 1-4.819 0 2.41 2.41 0 0 1 4.819 0Zm-29.819 0a2.663 2.663 0 1 1-5.326.001 2.663 2.663 0 0 1 5.326-.001Zm-30.327 0a2.919 2.919 0 1 1-5.837 0 2.919 2.919 0 0 1 5.837 0Zm-30.837 0a3.173 3.173 0 1 1-6.345.001 3.173 3.173 0 0 1 6.345 0Zm-31.346 0a3.428 3.428 0 1 1-6.856 0 3.428 3.428 0 0 1 6.856 0Zm-31.856 0a3.683 3.683 0 1 1-7.365 0 3.683 3.683 0 0 1 7.365 0Zm-32.365 0a3.937 3.937 0 1 1-7.875 0 3.937 3.937 0 0 1 7.875 0Zm-32.874 0a4.192 4.192 0 1 1-8.384 0 4.192 4.192 0 0 1 8.384 0Z\" fill=\"#FFF960\"\/><\/svg>\t\t\t\t<\/div>\n\n\t\t\t\t\n\t\t\t\t\n\t\t\t<\/div>\n\n\t\t\t\t\t\t\t<div class=\"header__second\">\n\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t<div class=\"header__branch-logos\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" src=\"https:\/\/fhi.nl\/app\/uploads\/2024\/02\/Industriele-elektronica.svg\" class=\"header__branch-logo\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t<\/div>\n\t\t\t\n\t\t<\/div>\n\t<\/div>\n<\/header>\n\n\t<div class=\"header__meta\">\n\t<div class=\"container\">\n\t\t<div class=\"header__meta__category\">\n\n\t\t\t\t\t\t\t<div class=\"header__meta__detail\">\n\t\t\t\t\t<div>Branch<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/fhi.nl\/en\/kennishub\/?_branches_kennishub=industriele-elektronica\" class=\"header__meta__detail--branch\">\n\t\t\t\t\t\t\t\tIndustrial Electronics\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\n\t\t\t\t\t\t\t<div class=\"header__meta__detail\">\n\t\t\t\t\t<div>Subject<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/fhi.nl\/en\/kennishub\/?_onderwerp_kennishub=industriele-elektronica\" class=\"header__meta__detail--categorie\">\n\t\t\t\t\t\t\t\tIndustrial Electronics\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/fhi.nl\/en\/kennishub\/?_onderwerp_kennishub=test-en-meetapparatuur\" class=\"header__meta__detail--categorie\">\n\t\t\t\t\t\t\t\tTest and measuring equipment\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\n\t\t<\/div>\n\t<\/div>\n<\/div>\n\n<div class=\"text bg--white\">\n\t<div class=\"container\">\n\t\t\t\t\t\t\t\t\t\t\t<div class=\"text__content text__content--1-col\">\n\t\t\t<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">Keysight Technologies has expanded its RF and microwave portfolio with a new generation of compact signal sources and synthesizers. One of the highlights is the\u00a0<a style=\"background-color: transparent;color: #000000;text-decoration: underline;font-family: Manrope, sans-serif;padding-bottom: 0px;margin-bottom: 0px\" href=\"https:\/\/www.keysight.com\/us\/en\/product\/AP4021A\/ap4021a-fs1-frequency-synthesizer-40-ghz.html#overview\">AP4021A FS1 Frequency Synthesizer<\/a>, a single-channel frequency synthesizer that combines low phase noise, excellent spectral purity, and ultra-fast frequency switching in a compact form factor.<\/p>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">Designed for demanding RF and microwave applications, the AP4021A enables engineers to perform high-precision measurements while improving test throughput in both laboratory and production environments.<\/p>\r\n<h3 style=\"clear: both;font-size: clamp(21px, 5vw, 32px);line-height: 1.2;font-family: Manrope, sans-serif;font-weight: 300;color: #002145;margin: 0px;padding-bottom: 30px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">Optimized for Modern RF and Microwave Test Applications<\/h3>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">As technologies such as radar, satellite communications, aerospace and defense systems, wireless infrastructure, and quantum research continue to evolve, test engineers require signal sources that offer both exceptional signal integrity and fast measurement capabilities.<\/p>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">The Keysight AP4021A addresses these requirements by generating signals from 10 MHz to 40 GHz with output power levels up to +20 dBm at 1 GHz. The synthesizer delivers outstanding signal purity, featuring phase noise performance as low as -145 dBc\/Hz at a 20 kHz offset from a 1 GHz carrier. This level of performance is critical for accurately characterizing oscillators, amplifiers, mixers, converters, and other high-frequency components.<\/p>\r\n<h3 style=\"clear: both;font-size: clamp(21px, 5vw, 32px);line-height: 1.2;font-family: Manrope, sans-serif;font-weight: 300;color: #002145;margin: 0px;padding-bottom: 30px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">Ultra-Fast Frequency Switching Improves Test Throughput<\/h3>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">A key differentiator of the AP4021A is its fast frequency switching capability. The synthesizer achieves switching times of less than 20 microseconds across its frequency range, enabling significantly faster automated test sequences and reducing overall test times.<\/p>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">This capability is particularly valuable in manufacturing environments and in applications that require the simulation of agile communication or radar systems, where rapid frequency transitions are essential.<\/p>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">In addition, the instrument provides millihertz frequency resolution, allowing highly precise frequency control for applications that demand exceptional stability and repeatability.<\/p>\r\n<p style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">\u00a0<\/p>\r\n<h3 style=\"clear: both;font-size: clamp(21px, 5vw, 32px);line-height: 1.2;font-family: Manrope, sans-serif;font-weight: 300;color: #002145;margin: 0px;padding-bottom: 30px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">Compact design for easy integration<\/h3>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">The AP4021A has been designed with system integration and automated test environments in mind. Its compact footprint allows engineers to maximize valuable bench and rack space while maintaining high RF performance.<\/p>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">For seamless integration into automated test systems, the synthesizer supports USB and LAN connectivity as well as the industry-standard SCPI-1999 command set. The internal reference can also be locked to an external programmable reference source, simplifying synchronization across complex measurement systems.<\/p>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">Additional capabilities include frequency sweeping, internal phase modulation, and narrow pulse modulation, providing flexibility for a broad range of advanced RF test applications.<\/p>\r\n<p style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">\u00a0<\/p>\r\n<h3 style=\"clear: both;font-size: clamp(21px, 5vw, 32px);line-height: 1.2;font-family: Manrope, sans-serif;font-weight: 300;color: #002145;margin: 0px;padding-bottom: 30px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">Part of Keysight&#039;s Expanded RF and Microwave Portfolio<\/h3>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">The AP4021A is part of Keysight&#039;s latest expansion of its RF and microwave test portfolio, which also includes new analog signal generators, vector signal generators, and signal source analyzers. Together, these solutions are designed to help engineers accelerate development cycles, improve measurement confidence, and increase production efficiency in next-generation RF applications.<\/p>\r\n<p style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">\u00a0<\/p>\r\n<h3 style=\"clear: both;font-size: clamp(21px, 5vw, 32px);line-height: 1.2;font-family: Manrope, sans-serif;font-weight: 300;color: #002145;margin: 0px;padding-bottom: 30px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">Technical Expertise from CN Rood<\/h3>\r\n<p class=\"isSelectedEnd\" style=\"margin-bottom: 0.5em;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">As an authorized Keysight distributor, CN Rood supports customers throughout the selection, implementation, and integration of RF and microwave test solutions. Our specialists can help identify the optimal signal generation architecture for your application, support automated test system development, and assist with the deployment of complete measurement solutions for R&amp;D, validation, and manufacturing environments.<\/p>\r\n<p style=\"margin-bottom: 0px;font-size: 18px;line-height: 32px;font-weight: 400;font-family: Manrope, sans-serif;color: #000000;margin-top: 0px;padding-bottom: 0px;font-style: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;background-color: #ffffff\">To learn more about the Keysight AP4021A FS1 Frequency Synthesizer and how it can enhance your RF test capabilities, contact the RF and microwave specialists at CN Rood.<\/p>\t\t<\/div>\n\t<\/div>\n<\/div>\r\n\t<div class=\"articles bg--offwhite automatic\">\r\n\t\t<div class=\"container\">\r\n\t\t\t<div class=\"articles__header\">\r\n\t\t\t\t\t\t\t\t\t<div class='heading-wrapper'><svg width=\"13\" height=\"13\" viewbox=\"0 0 13 13\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><circle cx=\"6.394\" cy=\"6.5\" r=\"6.394\" fill=\"#000\"\/><\/svg><h2>Related articles<\/h2><\/div>\t\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\/en\/profiel\/cn-rood\/\" class=\"button button--outline\">view profile<\/a>\r\n\t\t\t\t\t\t\t<\/div>\r\n\t\t\t\t\t\t<div class=\"post-grid post-grid--no-padding\">\r\n\t\t\t\t\n<a class=\"single-item single-item__articles\" href=\"https:\/\/fhi.nl\/en\/news\/application-note-gigavac-contactors-for-small-battery-pack\/\" data-id=\"37563\">\n\t<div class=\"single-item__articles-icon\">\n\t\t<svg width=\"103\" height=\"103\" viewbox=\"0 0 103 103\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n<path fill-rule=\"evenodd\" clip-rule=\"evenodd\" d=\"M49.5 98.9587V82.3076C33.3844 81.2758 20.6328 67.878 20.6328 51.5019C20.6328 35.1258 33.3844 21.728 49.5 20.6962V4.04134C24.1941 5.08952 4 25.9365 4 51.5C4 77.0635 24.1941 97.9105 49.5 98.9587ZM53.5 78.2983V61.8096H76.3238C72.5238 70.9498 63.8222 77.5397 53.5 78.2983ZM49.5 78.298V61.8096H26.681C30.4804 70.9484 39.1799 77.5377 49.5 78.298ZM47.0728 57.8096H25.3773C24.8906 55.7865 24.6328 53.6743 24.6328 51.5019C24.6328 37.3358 35.5955 25.7301 49.5 24.7058V37.013H34.0466C33.2709 37.013 32.5653 37.4615 32.2359 38.1637C31.9065 38.8659 32.0128 39.6952 32.5086 40.2916L47.0728 57.8096ZM55.9249 57.8096H77.6274C78.1141 55.7865 78.3719 53.6743 78.3719 51.5019C78.3719 37.3342 67.4068 25.7275 53.5 24.7055V37.013H68.9511C69.7268 37.013 70.4324 37.4615 70.7618 38.1637C71.0912 38.8659 70.9849 39.6952 70.4891 40.2916L55.9249 57.8096ZM53.5 82.3079V98.9587C78.8059 97.9105 99 77.0635 99 51.5C99 25.9365 78.8059 5.08952 53.5 4.04134V20.6959C69.6178 21.7254 82.3719 35.1242 82.3719 51.5019C82.3719 67.8796 69.6178 81.2784 53.5 82.3079ZM0 51.5C0 23.7271 21.9843 1.08883 49.5 0.0381213V0H51.5H53.5V0.0381213C81.0157 1.08883 103 23.7271 103 51.5C103 79.9427 79.9427 103 51.5 103C23.0573 103 0 79.9427 0 51.5ZM38.3102 41.013H64.6875L51.4989 56.8765L38.3102 41.013Z\" fill=\"#2DD881\"\/>\n<\/svg>\n\t<\/div>\n\t<div class=\"single-item__articles-title\"><div class='heading-wrapper'><h3>APPLICATION NOTE: GIGAVAC CONTACTORS FOR SMALL BATTERY PACK<\/h3><\/div><\/div>\n\t<div class=\"single-item__articles-terms\">\n\t\t\n\t\t\n\t\t\t\t\t\t<span class=\"button button--outline single-item__articles-term--branche single-item__articles-term\">Industrial Electronics<\/span>\n\t\t\t\t\t\t\t\t<span class=\"button button--outline single-item__articles-term--branche single-item__articles-term\">Electronics &amp; 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One of the highlights is the AP4021A FS1 Frequency Synthesizer, a single-channel frequency synthesizer that combines low phase noise, excellent spectral purity, and ultra-fast frequency switching in a compact form factor.<\/p>","protected":false},"featured_media":84564,"template":"","branches":[13],"events":[361,9,60,370,8],"secretariat":[41],"categories":[57,22],"themes_tax":[511],"content_types":[514],"class_list":["post-84563","news","type-news","status-publish","has-post-thumbnail","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.1 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Keysight AP4021A FS1 Frequency Synthesizer Delivers Low Phase Noise and Ultra-Fast Frequency Switching<\/title>\n<meta name=\"description\" content=\"The\u00a0AP4021A FS1 Frequency Synthesizer, a single-channel frequency synthesizer that combines low phase noise, excellent spectral purity, and ultra-fast frequency switching in a compact form 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