The 2021 International Microwave Symposium presented new coax and waveguide technologies including mmWave connectors. After a virtual year, Bishop & Associates’ David Shaff visited the 2021 show in person. Here’s what he saw.

2021 IMS

After a year of COVID-19 lockdowns, attendees were anxious to attend the 2021 International Microwave Symposium (IMS) live event, to meet with colleagues and see new products in person. The IMS, held June 7-10 at the Georgia World Convention Center (GWCC) in Atlanta, also included an expanded virtual conference, held June 20-25. Registration for the live event included full access to the virtual symposium, and those who could not attend in person had the opportunity to experience a version of the show.

International Microwave Symposium is part of the Microwave Week, which also includes the RFIC (Radio Frequency Integrated Circuits Symposium) and the Microwave Measurement Conference, hosted by the Automatic Radio Frequency Techniques Group (ARFTG). Ongoing global travel restrictions prompted the IMS and RFIC to hold overlapping sessions, while the ARFTG was held only as a virtual event on June 24.

2021 IMS exhibition floor

The exhibition area at IMS 2021 maintained social distancing with aisles that were twice the usual width.

Although most Asian companies and many European exhibitors were missing from the exhibition floor, larger multi-national firms with strong U.S. operations were present, including Rosenberger North America, Mini-Circuits, Rohde & Schwarz, and Telegärtner. While silver sponsor Keysight Technologies had the largest exhibition area when combined with its industry partners, many usual exhibitors, including Hirose Electric, Anritsu, Maury Microwave, and Southwest Microwave, participated only in the virtual exhibition. (Read David Shaff’s review of the 2020 virtual IMS show and the 2019 IMS event held in Boston.)

Intel Corporation’s Vice President Asha R. Keddy, the IMS keynote speaker, said, “The additive nature of today’s technology megatrends, such as 5G, AI, IoT, edge computing, and the cloud, is fueling the need to converge into one intelligent, resilient, and distributed networking fabric.” Exhibitors reinforced that at the higher frequencies of 5G and 6G, mechanical components such as connectors are characterized by their electrical performance, alongside active and passive devices in the same circuits.

The Virtual IMS had six parallel technical sessions, 35 workshops, three technical lectures, as well as MicroApps and Industry Workshops. Registered attendees had worldwide access to all Microwave Week events. Prompted by all the new frequencies and protocols for 5G, many papers focused on filtering, antenna-in-chip packaging, and test methods.

mmWave application

The magnitude of mmWave applications is illustrated in this slide from Stanford University Professor Amin Arbabian.

Microwave business was not slowed by Covid-19

Although COVID-19 reduced microwave symposium attendance, most exhibitors said that the pandemic had not slowed down technical advancement nor their bookings. A consensus of connector companies reported excellent current bookings versus COVID-19-induced downturns in 2020 and early 2021, while firms in the mil-aero market saw little or no reductions during that same time. (This tracked the forecasts made by Bishop & Associates in the 2020 World RF Coax Connector Market report.) The biggest concerns related to material shortages and longer lead times, plus increased materials costs. Rogers Corp. plans to use copper/material “cost/price adders,” while most connector firms at IMS said that they were adopting a short-term wait-and-see attitude. Positive business results were reported by Subi Katragadda, general manager of SV Microwave (Amphenol), who recapped the company’s expansion into a new facility in Mesa, Arizona. SV Microwave presented new products onsite and virtually, including keyed SMA, locking SMP/SMPM, and connectors/cables for quantum computer cryo-chambers.

SV Microwave RF connectors

SV Microwave presented RF connectors and cables for quantum computers. These connectors and cables may be required to perform in extreme cold temperatures or may be used in between the stages of the “chandelier” where hermeticity is required.

As an engineer who normally focuses on technology, I was reminded of the difficulties of small businesses when Bob Hawkins, president of Centric RF, reported, “We’ve experienced fast growth before and during COVID. Our larger disruptions have been the China tariffs and sales tax collections due to the South Dakota vs. Wayfair Supreme Court decision.”

Most component industry companies were absent. However, CNC provider Bob Kroll, a company that works with many connector suppliers, was there with Tooling Dynamics, extolling the company’s ability to machine with tolerances of 50 microinches needed for mmWave components.

Test equipment highlights

Copper Mountain Technologies, Keysight, and Rohde & Schwarz all exhibited new mid-range equipment that emphasizes greater bandwidth and faster test cycling. While technical papers focus on higher frequencies promoted by 5G and 6G, this reminds us that over 80% of coax interconnect is still for 10 GHz (including LTE and 5G WiFi requirements for 6 GHz with future potentials for 7.1 GHz) and under. Mini-Circuits introduced its new portable VNA for 6 GHz (emphasizing “low cost”) along with higher-end 60-70 GHz MMICs and solid state power amplifiers (SSPAs).

An engineer from Keysight Technologies walked me over to the Virginia Diodes Inc. (VDI) booth to see Keysight’s new portable Streamline Series P5024A VNA with VDI extenders running 90-140 GHz. Virginia Diodes has become an industry leader for THz measurement, and the company presented a paper at the MicroAmps session on waveguide technology and THz applications for 6G.

The virtual ARFTG session had papers on calibration and metrology standards. Virtual presentations by Maury Microwave covered measurement uncertainty analysis using its Insight software to present how data points really are areas representing the probability of results, which becomes extremely important at the higher 5G and 6G frequencies.

mmWave frequency bands

Communications systems continue into higher mmWave frequency bands.  Illustration from MicroAmps presentation by Anritsu.

Microwave and mmWave Connectors and Microwave Accessory Highlights

Production of 110 GHz W Band connectors is now almost commonplace, with exhibits at IMS by Amphenol/SV Microwave, Rosenberger, Samtec, Conduct RF, Eravant (including 1 mm to waveguide adapters for 40-125 GHz), Junkosha, plus precision test versions by Rosenberger and Keysight. Additional virtual IMS exhibitors showing 1 mm connectors included Johnson (Cinch Connectivity Solutions), Anritsu, HuangLiang (Taiwan), Southwest Microwave, Superlink Technologies (Shenzhen, China), Waka Manufacturing (Tokyo), and WL Gore (cables). Due to developing 6G potentials for connectorized D Band components (corresponding to WR6 and WR7 waveguides operating 110 GHz to 170 GHz), new suppliers for 0.8 mm connectors (following Anritsu’s initial use for its 145 GHz VNAs) are Junkosha, with its own precision phase-stable cables for 145 GHz, and GBB Industries for its probes.

Prompted by the 5G NR Band “n259” for 39.5 to 43.5 GHz, many components were seen rated to 44 GHz with enhanced 2.92mm connectors. SV Microwave presented VITA 67.3 multi-position coaxes in accordance with new Sensor Open Systems Architecture (SOSA) U.S. military inter-service standards.

Hirose miniature board coax C.FL series

Hirose Electric continued to emphasize miniature board coax in a virtual presentation of the new C.FL series, operating DC to 30 GHz with tactile locking and mated height of 0.92mm, for 5G communication devices and CPE (Customer Premise Equipment).

mmWave Connectors

New test equipment often spawns new interconnects, and the use of 1.35 mm (E Band, 90 GHz) connectors by Rohde & Schwarz has resulted in E Band connectors, shown by Rosenberger, Samtec, Eravant, and Southwest Microwave (virtual). To support 5G product development, Rosenberger displayed kits suitable for lab or field use with a variety of precision adapters, test cable assemblies, calibration grade terminations and attenuators, plus torque wrenches, in a handsome wood case.

Samtec, a first-time Corporate Sponsor for IMS, exploded on the scene with multiple new series of microwave and mmWave connectors, including SSMA, 3.5mm, 2.92mm, 2.40mm, 1.85mm, 1.35mm, SMPM, and 1mm, with solderless compression-mount board launches and cable assemblies. The company’s Flyover® QSFP28 cable assemblies tout 70 GHz. Samtec’s most unique product shown at IMS was its small form factor, highly flexible waveguide assemblies with threaded termination to right-angle PCB mount launches. Mike Dunne, Samtec’s director of microwave products, advised that, “It’s in Phase 2 of development and test and will be a highlight of our new mmWave connector products.”

New Technology in Microwave Packaging

3DFortify Inc. and PCB laminate material supplier Rogers Corp. presented a new joint program for 3D printing low-loss dielectric materials with multiple physical gradients that provided tunable permittivity, to serve 5G and future 6G needs for wide bandwidth, active antenna systems (AAS) for microwave communications, and sensing components. Specific applications range from passive mmWave beamforming and beam switching antennas to producing Luneburg lenses for higher GHz frequency antennas. Printing allows rapid modification to upgrade performance or physical configuration.

Significant advances in waveguide and waveguide-to-coax packaging were featured by corporate co-sponsor Eravant (previously Sage Millimeter). Its Uni-Guide Waveguide Connectors provide compact, cost-effective waveguide flanges that are easily swapped with coaxial connectors to enable flexibility for component manufacturers and end-users. Unique cavities in the WG connector enable WGs and coax connectors to be turned 90-degrees while maintaining electrical performance, rather than having to design and produce new housings.

IMS 2022

Attendees and exhibitors alike are looking forward to IMS 2022, June 19-22, 2022, in Denver. Deferred international travel and rapidly advancing technology suggests that IMS 2022 may set a record for both attendance and exhibitors. “The Connected Futures Summit” and “RF Tutorials” sessions are already being planned. Bishop & Associates is planning to be there to continue our reporting on ongoing advancements in RF, microwave, and mmWave connectors and interconnects.

Like this article? Check out our other New Technology, 5G, Trade Shows, and our Datacom Market Page, and our 2021 and 2020 Article Archives

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