The allocation of mmWave bands for 5G has opened a new market for cable assemblies and connectors, although Southwest Microwave and SPINNER offered mmWave cable assemblies prior to the arrival of 5G. Molex and Samtec are starting to see interest in mmWave cable assemblies. Molex says although “mmWave deployments are fewer than anticipated,” it has “many development projects with strong customer interest in this area.” Samtec says it has “slowly seen some new mmWave applications” between 30 and 40 GHz. With 5G eyeing bands to 56 GHz, CAES sees the need to extend the frequency coverage of low loss, phase-matched cable assemblies for base stations and T&M systems.

In addition to the electrical performance, Gore says customers need “extremely robust and rugged assemblies that can provide consistent performance and reliability over time.” With all the attention on deploying systems in the field, we sometimes overlook that 5G systems must first be tested. Maury Microwave cautions that the testing requirements for 5G and the newest Wi-Fi standards “are so demanding that even the best cable assemblies can impact measurement results.” Combining Maury’s T&M cable assembly and test system expertise, it has focused on quantifying the uncertainties of 5G and Wi-Fi measurement systems. Using that insight, it can improve its own cable assemblies and help companies understand the error contributions from each system component on the measurement results to ensure accurate characterization of their products.

ABOVE 5G

Samtec 1.35 mm cable assemblies and connectors support applications to 90 GHz. 

 

5G is not the only market tapping the mmWave spectrum. Point-to-point radio links and automotive radar came before 5G, and 60 GHz has long been promoted for personal area networks and is being used in several locales for short-range fixed wireless access. Some researchers, already bored with 5G, have started working on 6G, eager to tap the unlimited bandwidths above 100 GHz. Will cable assemblies support these applications or will we see a resurgence of waveguide?

HASCO has extended its active and passive products to 110 GHz to support emerging applications such as synthetic radar, communications and defense. Encouragingly, SPINNER notes a surge in demand for connectors, adapters and cable assemblies between 40 and 90 GHz. Samtec is also bullish on these new bands, developing products for the 40 to 90 GHz range, particularly 80 to 90 GHz. Samtec recently released a 1.35 mm family including compression-mount board connectors and flexible .047 cable assemblies offering 1.35 mm male or bulkhead female connector options. Looking higher, it is developing 1.00 mm cable assemblies to reach the 110 GHz benchmark.

Pasternack says it is betting on cable assemblies and waveguide, investing in test equipment and components to build both. Like Pasternack, Mini-Circuits sees the demand for mmWave and sub-THz applications “growing fast,” particularly in T&M, which necessarily leads market development. Responding to these opportunities, the company says, “We’ve invested heavily in the design talent and facilities to expand our portfolio for cables, adapters and attenuators, as well as other connectorized products, including amplifiers up to 110 GHz.” Mini-Circuits has launched its first waveguide to coax adapters and plans to build out its selection of waveguide products.

Southwest Microwave custom multi-port cable assembly. 

 

Molex has a strong position in automotive, particularly automotive antennas, and worked with Rosenberger to develop the High-Speed FAKRA Mini interconnect, which has 20 GHz bandwidth for relaying radar, camera, LiDAR and sensor data throughout the vehicle. Since the automotive market has not yet adopted mmWave for communications, Molex is working on mmWave sensing applications while developing the capability for mmWave communications, borrowing technology from its capabilities in base stations.

Both CAES and Gore are researching ways to serve market needs at these higher frequencies, CAES examining novel structures and new materials for designs above 60 GHz. Vertically integrated from R&D through manufacturing, Gore is exploring cable materials and connector options to extend frequency coverage, working with customers to ensure the new test assemblies will meet Gore’s standards for accurate, reliable and repeatable measurements.

DEFENSE MARKET TRENDS

Microwave Journal asked about defense market trends and new requirements from military systems. CAES provided a list of emerging requirements for interconnects:

  • Multi-function assemblies requiring multi-function interconnect mating: video, RF, microwave, mmWave and analog/DC cables packaged in multi-pack configurations
  • Interconnects capable of hypersonic environments, i.e., able to withstand high shock and high temperature
  • Smaller and lower weight interconnects for military and space systems, particularly low Earth orbit (LEO) applications.

Molex sees requirements for cable assemblies for surveillance systems and military communications. Gore cited upgrades to radar warning receiver, airborne electronic surveillance, countermeasure systems and other electronic warfare systems that include upgrades to the RF, microwave and mmWave components. Common themes from these upgrades are higher power, higher frequency and higher density coax assemblies for airframes.

Pasternack endorses the need for higher frequency coverage and size reduction to accommodate more compact footprints. Higher port count array antennas are driving custom compact interconnects, including edge-mount and spring probe connectors. Likewise, Samtec sees increasing need for higher frequency operation, to 110 GHz, and dense connector packaging, such as ganged SMPM board-to-board and cable-to-board products for phased array antennas. Samtec is also researching ways to make waveguide assemblies more flexible and cost effective.

COMMERCIAL SPACE

Pasternack low PIM cable assemblies.

 

The commercial LEO satellite market is growing, enabled by lower cost rocket launches and less stringent requirements for lower orbit operation. We asked how this opportunity is changing the requirements for cable assemblies and influencing product development.

CAES noted requirements for higher frequency coaxial solutions with novel interfaces and very low RF susceptibility. These add to the standard requirements for ruggedness, small size, light weight, low insertion loss and, in some cases, phase-matched sets. Commenting on the need for higher frequencies, Samtec is seeing demand for cable assemblies for the 40 to 50 GHz band to complement the other satellite bands in use. The company is also developing cable assemblies to meet more stringent environmental requirements for future applications.

Southwest Microwave said it is seeing opportunities to support LEO satellites, as it is “well known in the space industry for being able to supply great performance with very small footprint.” HASCO noted that it has seen increasing demand for waveguide assemblies for satellite constellations such as Starlink. Pasternack added the need for cable assemblies for the RF/microwave components in the satellite ground stations, which link the LEO constellations to terrestrial communications networks.

THREAT OR OPPORTUNITY?

We asked whether so many systems becoming multi-beam phased arrays requiring over-the-air (OTA) testing was a threat to the C&C market. The companies that responded actually see OTA testing as an opportunity.

SPINNER waveguide to coax adapters cover V-, E-, W- and F-Bands.

 

CAES said wireless testing increases cable demand, with multi-function chip sets requiring more complex testing and interconnects between the chip set and measurement system. Gore has a similar view, “It is an opportunity for high performance microwave/RF cable assemblies to reduce test scheme complexities and increase throughput.” Gore offers the example of high volume OTA testing inside a test chamber, a set-up using long cable assemblies “that must be very stable and have very low VSWR to ensure repeatable and reproducible test results.”

Molex looks behind wireless OTA testing to the backbone infrastructure, which must have high data rate coaxial connections. Pasternack’s view is that OTA test systems still require interconnects, more than in the past because of high element phased array antennas and the test equipment ports to measure them. Given all these ports, HASCO sees the opportunity to develop more robust cable lines with shorter lengths and smaller diameters to reduce system and test space and weight. SPINNER reminds us that the test equipment for wireless systems must be pre-qualified and calibrated to eliminate linear errors and improve measurement accuracy.

THE FUTURE

We asked the companies to share the opportunities they see on the horizon, wondering if quantum computing is one of those.

CAES listed several opportunities: 1) Hypersonic airframes with the challenges of high temperature, high G and high shock. 2) mmWave active phased arrays for LEO constellations, with the need for novel interconnects. 3) ELINT and SIGINT systems pushing broader bandwidth and low loss. CAES is monitoring quantum computing, which requires low temperature and low loss interconnects, and has not yet decided whether to engage in this market.

Gore remains committed to its core mission, precision testing of mission-critical electronic systems, and will apply its capabilities to serve new markets as they develop.

HASCO sees the growth of 5G and IoT applications as a major opportunity for RF/microwave cable assembly suppliers. Wireless broadband, whether cellular or Wi-Fi, will require large numbers of micro base stations throughout municipalities, maintaining a steady demand for new cable components.

Maury Microwave noted the expanding opportunity for high accuracy measurements at higher frequencies. With the increasing complexity of measurements, T&M users must understand the impact of each component in the measurement system. Cable assemblies can be problematic and should not be treated as ideal components, particularly with extended use. The uncertainty caused by the cable assembly should be quantified and reduced where possible.

Molex sees significant growth opportunities in vehicles, including automobiles, commercial vehicles, recreational vehicles and e-bikes. All will need miniaturized coaxial interconnects to carry the data from an increasing number of high data rate sensors.

For Pasternack, IoT, commercial space and mmWave industrial applications offer growth, as well as the traditional aerospace and defense applications. Accessible and modular test equipment is also creating requirements for new test interconnects.

Samtec has long participated in standards committees, recently working on the new VNX+ standard to bring RF and fiber to the VNX form factor. Samtec sees this as a significant growth opportunity in addition to extending its product portfolio to 110 GHz. Samtec views quantum computing as a growth market that can be supported with minor modifications to its standard products. Entering this market will require a testing program to verify these modifications will perform as expected in the quantum environment.

Looking to its future growth, Southwest Microwave adds higher frequency phased arrays covering 20 to 70 GHz and multi-signal connectors handling RF, digital and power.

CONCLUSIONS

Although the C&C industry may seem mature, it is dynamic, reflecting the trends and needs of the many applications it serves. The future offers many opportunities, from connecting the front-end in a hypersonic missile seeker to a phased array on a satellite or a 5G mmWave base station. The overarching requirements driving the industry are higher frequencies, higher port density, smaller size, lower weight and consistency over time and the environment. Like other segments of the RF/microwave component industry, C&C suppliers are consolidating, yet a strong base remains. This is reflected in the responses from the 10 companies that participated in our survey. We appreciate their willingness to share their perspectives.