New Microwave and RF Advances Impress at IMS2024
The technical advances showcased at this year’s event were outstanding. More than ever, IMS is much more than an exhibition.
The IEEE MTT-S International Microwave Symposium, held June 16-21, 2024, in Washington, D.C., combined the RFIC, IMS2024, and ARFTG conferences. The event brought together the foremost entities in the global RF industry, from ICs to sensors to connectors, cables, optical products, and waveguides, for a week-long series of technical presentations, workshops, and focal sessions, plus the ARFTG Microwave Measurement Symposium. Exhibitor numbers almost returned to pre-pandemic levels, with 548 exhibiting companies, including over 80 first-time exhibitors. Preliminary registration was under 7,800, which grew with additional onsite registration, but was still way under last year’s gathering of over 9,000 attendees. Discussions indicated that companies sent key staff but kept this to a minimum.
Responses to “How’s business?” ranged widely, with niche distributors reporting “flat” business levels as customers used-up the inventory double-ordered during the pandemic. However, several specialty manufacturers reported YOY increases of 25-35% for the first half 2024 over 2023. Nobody reported cutbacks in product development and exhibitors displayed new products resulting from these endeavors, which made this event very worthwhile.
This year’s IMS included more than microwaves. Wednesday featured a panel session on climate change, plus Women in Microwaves (WIM) presented a joint panel with the Young Professionals and an evening reception. IEEE’s special MOVE (Mobile Outreach VEhicle) truck was parked in the exhibition area to showcase the work IEEE does for disaster relief by providing capability for high-speed satellite uplink for WiFi internet and communications when other sources are inoperable. Continued standardization of higher frequency interconnect was supported by meetings of IEEE working groups P1785 and P3136 on waveguides.
IMS2024 also included a unique Start-Up Program with special exhibition and networking areas. Thintronics Inc. (San Francisco, CA) presented one of the more creative entrepreneurships, using unique PCB materials to enable wider bandwidths and increased power efficiency for advanced computing and communication systems.

Presentations at the Microapps Theater in the exhibition area were well attended.
While high-tech fascination focuses on the newest, smallest, and highest-frequency connectors, the bulk of RF/microwave interconnect business is still 6 GHz and below. Molex presented its new MMCX PoC (Power over Coax). Roger Kaufmann, senior director of product management for Molex, described how current MMCX plugs use a half-round snap ring in a groove that allows movement of the mated connector pair, which can cause intermittent power levels that becomes a significant issue for critical sensor or video applications. Molex’s solution is a new spring mating technique that eliminates the intermittent condition even when mated with industry standard MMCX PCB jacks.

Molex’s new MMCX Power-over-Coax Plug, for DC to 6 GHz. (Photo by Molex)
New connectors extend frequency limits
At IMS last year, several firms displayed new 0.8 mm connectors (helped by the interface standards IEEE 287-2021 and IEC 61169-64), but this year they also showed test data. Exhibitors with 0.8 mm connectors or adapters included Anritsu, FLANN Microwave, Southwest Microwave, SPINNER, Waka Manufacturing, and Yuetsu Seiki, plus Chinese suppliers Lanjian Electronics and Suzhou Talent. Microwave results are illustrated below (VSWR is 1.51:1 for back-to-back assembly with pin; connector itself is 1.24:1 through 145 GHz):

Graphics courtesy of Southwest Microwave
Sometimes being “long” in the industry lets you learn confidential things that may not yet be public, such as the growing trend toward multi-port multi-coax assemblies either linear (in a row) or as coax-inserts installed in multi-cavity connectors. Interfaces for SMPM and SMPS/SMP3 (finally) have been standardized, but concern remained that different recess/interfacial depths of the coaxes may affect intermateability. Do both mating sides have to be from the same supplier, to avoid issues similar to “decades old” SMP/GPO intermate problems? This writer was told that several suppliers successfully conducted intermateability testing with D38999 assemblies using SMPM interfaces for contact size 16 (and probably larger cavity sizes) involving vibration, etc. Reports are not yet public, but suppliers would be those common to VITA 67 and SOSA. Coaxes for the small size 20 contact cavities (operational to 110 GHz) of MIL-PRF-24308, MIL-DTL-38999 (all four series), and even new MIL-DTL-32689 circulars still are sole source. Bishop & Associates will report further on multi-sourced intermateability as information becomes available.
New cable meets industry needs
From test equipment suppliers to cable houses, the emphasis was on low loss coax cable with phase stability and bend-radius flexibility for 65 GHz and higher. This year, suitable cables were presented by Samtec, Custom Cable, evissaP, Glenair, HASCO, MegaPhase, Shenzhen Superlink, Withwave, Yuetsu, and others. MegaPhase also showed its space qualified ultra-low loss cable for up to 67 GHz performance, along with armored crush-proof cables for rough test and severe environment applications to 18 GHz. Harbour Industries offered low loss, high temperature, and MIL-STD-17 types.

Littlebend ultra-flexible cable offered by HASCO Components, is phase and amplitude stable, for dense microwave packaging with a 0.20” minimum bend radius in an 0.098” cable with stainless steel braid. (Photo complements of HASCO Inc.)
Samtec released its new Nitrowave next-generation family of RF coaxial cables, which are phase and amplitude-stable with flexure, ranging from 0.047” to 0.277” with OD and bend radius as low as 0.125”. The coaxial cables have an outer jacket colored in distinctive Samtec orange and will be produced in Samtec’s new factory in Royersford, Pennsylvania.
Samtec has been rolling out many new mmWave connectors, including 1 mm and 1.35 mm plus state-of-the-art flexible wave guide assemblies (shown below). Danny Boesing, Samtec’s product marketing director, reported that they had to overnight additional catalogues twice due to high attendee interest. The company’s new downloadable Precision RF Catalog, which includes test data, features Samtec’s new coax cable and assemblies (page 8) and its unique flexible waveguide technology (page 12).
Applications for non-magnetic connectors include quantum computers, MRIs and other medical equipment, test labs, aerospace, and space. Connector types offered varied by supplier, but included MMCX, MCX, SMPM, SMA, N, and 2.92, offered by Johnson (Cinch/belfuse), Rosenberger, Signal Microwave, SV Microwave, Winchester Interconnect, and Withwave.
NMD receptacles (named for the Network Measurement Division of Hewlett Packard, now Keysight Technologies) are used for test equipment ports and mating cables. These are needed for both RF and new mmWave higher frequency connectors/cables and were displayed by Anritsu, Junkosha, Lanjian Electronics, Keysight, MagaPhase, Maury Microwave, Mini Circuits, Southwest Microwave, Suzhou Talent, and Withwave.
Corning Gilbert announced new (reportedly industry’s first) gold-over-nickel plated ABS-plastic (housing) microwave connector that is up to 33% lighter than similarly sized Corning Gilbert beryllium copper-based GP*-family of interconnects, for DC to 26.5 GHz applications. The center contact is traditional BeCu with gold-over-nickel plating. These POLYLINK connectors have reduced manufacturing lead times, compatible interfaces, and performance up to 26.5 GHz. The literature states that they are single-use connectors, rather than the 50 to 500 mating cycles offered by their BeCu counterparts, but the weight and cost savings may be suitable for appropriate applications.
SOSA requirements served with new VITA connectors
As our readers may know, SOSA (Sensor Open System Architecture) is a consortium of government, U.S. military, and industry representatives, established to support the Department of Defense’s 2013 Procurement Directive that all future acquisition activity must incorporate Open Systems Architecture principles and practices. SOSA aims to accelerate the deployment of modular systems using an open architecture that reduces development costs and permits interchangeability of similar equipment between all services, using existing and new standards by VITA (VMEbus International Trade Association).
SOSA interconnects include backplanes, plug-in cards using (prior) OpenVPX, open-field pin arrays, high-density circular connectors, and front-end plug-in arrays, involving RF/coax, fiber, and copper wiring. It has taken time to establish standards, design, and produce products, but resulting interconnects are becoming available. They were included in IMS2024 exhibitor presentations by Delta Manufacturing, Samtec, SV Microwave (Amphenol), Smiths Interconnect, and others.
SOSA-aligned products are primarily COTS designed with SWaP-C (Size, Weight, Power, and Cost) objectives. Accordingly, they are being designed into both commercial and mil-aero systems with industry growth being watched by many manufacturers as new components and assemblies are released.

At left above, VITA sample chassis with backplane connector modules including hybrid coaxial and Fiber Module with 9 SMPM 67.3 Contacts and 1 MT fiber contact. At right is sample assembly with VITA Plug-In Connector Modules with hybrid coaxial and fiber module. (Courtesy of SV Microwave)
Test Equipment Advances
Major test and instrumentation suppliers presented new wares. Copper Mountain Technologies showed miniature VNAs that could be embedded within sensor applications. Anritsu displayed its VectorStar ME7838x4 Broadband systems provide high-performance 4-port measurements for measurements up to 220 GHz. It incorporates Anritsu’s MA25400A mmWave module and uses a 0.6 mm test port connector, the smallest connector employed today. Keysight offers its S93301B Broadband VNA Operation to 220 GHz for on-wafer device characterization of emerging 5G and 6G MMICs with a single sweep from 900 Hz to 220 GHz, provided by upgrading from its 125 GHz VNA configuration with N5295AX frequency extenders. When asked if they were working on a 0.5 mm connector for future VNAs, a Keysight representative said that they could neither deny nor acknowledge any work on a 0.5 mm connector. Interconnect technology moves on.
A key application for higher frequency test equipment capability is on-wafer probing to serve the semiconductor industry. Besides millimeter performance, application needs include higher temperature and extended differential-pair probe tips. Anritsu showed how to calibrate/measure this using its VectorStar ME2728D4 system. Advanced probes were offered by GGB Technologies (Picoprobe) and Signal Microwave.
Waveguides are important
As 5G rolls out and industry begins planning for 6G, waveguides become an increasing portion of interconnect. IMS2024 had almost equal numbers of exhibitors listing “waveguides” and “connectors/adapters.” Waveguide-to-microwave components are usually are called adapters, but the correct technical term is transitions. Transitions were exhibited using connectors from SMA up to 0.8 mm, offered by CentricRF, ERAVANT (formerly Sage Microwave), Flann Microwave, Keysight (referencing its website), Maury Microwave, Mini Circuits, Narda-Miteq, Pasquali Microwave, and others. Waveguide switches were offered by several exhibitors, including Flann Microwave, Logus Microwave, Microwave Communications Laboratories, QuinStar Technology, Sector Microwave, and A-Info (China).
Besides exhibiting a wide variety of high frequency wave guides, Microwave Development Laboratories (MDL) handed out old-fashioned carboard slide charts that provide cross-referencing and support data such as frequency range and dimensions for EIA-designated rigid waveguides. (See this information online.)

Waveguide to coaxial transitions by Smiths Interconnect’s|TRAK Microwave.
Although popular and multi-sourced, waveguide-to-coax adapters usually are bulky and expensive, plus they introduce additional circuit loss, which can degrade overall performance and increase cost. On the other hand, a dedicated package with built-in waveguide transition option normally requires costly special design and manufacturing. Eravant displayed its recently invented and patented waveguide connector to overcome these difficulties. Instead of having a separate coax connector, these WG connectors accept the industry standard 0.012” diameter glass bead with 0.48” mounting hole. The input and output waveguide port can be aligned orthogonally by simply turning one port 90° relative to the other port.
Above, Eravant’s WR-19 waveguide connector with interface for 0.012” diameter pin for coax transmission eliminates the need for a separate coax connector. Being a new concept, designers will have to learn a different approach for transitions. (Photo courtesy of Eravant.)
To support industry expansion, Bishop & Associates is including waveguides in its market reports, starting with its World RF Coax Connector Market 2023 report.
The next IEEE MTT-S International Microwave Symposium will be held June 15-20, 2025, in the George R. Moscone Convention Center in San Francisco. IMS2025 will continue as a combination of the RFIC, IMS, and ARFTG Conferences, to be the world premiere venue for the RF/microwave industry. I look forward to joining you there.
To learn more about the companies mentioned in this article, visit the Preferred Supplier pages for Cinch (Belfuse), Molex, Rosenberger, Samtec Inc., Smiths Interconnect, SV Microwave, and Winchester Interconnect.
Like this article? Check out our other articles on Trade Shows, Test & Measurement, and our Wire and Cable Assemblies Market Page, and our 2024 Article Archive.
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