FAQ: Everything You Need to Know about 5G mmWave and Sub-6 Antennas
June 24, 2021
June 24, 2021
5G brings instant, reliable machine-type communication (MTC) across verticals to support new and existing applications. Millimeter wave (mmWave) and sub-6 GHz are definitive parts of this new 5G landscape.
5G’s massive multiple-input multiple-output (MIMO) antennas multiply the radio linkage’s spectral efficiency, critical for higher frequencies. These antenna arrays can reach hundreds of elements in mmWave bands, enabling mmWave radios to form and guide electromagnetic energy beams.
Sub-6 GHz spectrum is being re-farmed worldwide from sunsetting 2G and 3G networks. These frequencies are ideal for wide-area coverage, as they travel farther and through more obstacles than mmWave.
Experts from Telit, Taoglas and Qualcomm Technologies, Inc. have answered the top questions about 5G, mmWave and sub-6 GHz. Discover what you need to know about regulatory issues, use cases, isolation techniques and more.
VP Strategic and Channel Sales, Telit
Regional Product Marketing Director, Telit
Lead Engineer – Millimeter Wave Projects, Taoglas
Director of Product Management, Qualcomm Technologies, Inc.
Safi Khan, Telit: The mmWave antenna for mobility would be the low-power (LP) version from Qualcomm Technologies (QTM525 LP mmWave antenna). There are no other options.
Jeff Clemow, Telit: Sub-6 and LP mmWave will support mobility while high-power (HP) mmWave supports static use cases. Sub-6 improves uplink over LTE, so for the next step up from 4G LTE High Category (Cat), 5G sub-6 is the right choice. For high bandwidth, mmWave will be the best option.
Safi Khan, Telit: Major mobile operators spent billions of dollars to acquire C-Band spectrum. The FCC has mandated that they pay spectrum clearance fees. These fees also cost a few billion dollars to pay the incumbent satellite operators to clear the spectrum.
Jeff Clemow, Telit: mmWave is different from LTE and 5G sub-6 due to the mmWave antenna being an active antenna design. For North America, the FCC requires end-device certification at the system level. This requirement complicates existing certification plans and production.
The 5G module and antenna design must be calibrated for the end device, which is a new step in manufacturing end products. You will have to add code during production for the antenna. There is no option for an easier path.
The best mitigator of the challenge is having a trusted partner, which is how we position ourselves with our customers.
Jeff Shamblin, Taoglas: A 60 mm board is too short to meet the efficiency requirements needed to pass certification at the 600 MHz band. An 80 mm board or longer is recommended to meet the minimum antenna efficiency requirements when coupled to a small PCB’s ground layer.
Anand Venkataraman, Qualcomm Technologies: Our modem-RF systems are designed for global band support, including mmWave, sub-6 and legacy LTE bands. For mmWave, our modem-RF solutions support n258 (24.25-27.5 GHz) for North America, Europe and Australia, in addition to the following bands:
We’re at the forefront of supporting the newest 5G bands expected to commercialize, such as 41 GHz band n259 and new sub-6 bands like n53 and n70. We have a superior modem-to-antenna solution for challenging low-frequency LTE bands such as B71 (600 MHz).
Jeff Clemow, Telit: The primary barrier of mmWave will be that it requires a line-of-sight view of the tower. The beamforming requirements will make designs more complicated. Any use case that requires high bandwidth, especially on the uplink, will opt for mmWave.
Other barriers are mobile network operator (MNO) deployment timelines and support with backhaul to maximize network performance.
Safi Khan, Telit: It would depend on the design of the end-user devices. The antennas need to be under a radome, so they can be internal antennas as long as they can “see” the signal from the small cell.
Jeff Clemow, Telit: The 3GPP Release (Rel) 16 chipsets will be coming out with the first iteration software by the end of the year. Modules will be another six to nine months before they’re available in mass production volumes.
Anand Venkataraman, Qualcomm Technologies: The Snapdragon X65 is the world’s first 10 Gigabit 5G and the first 3GPP Rel 16 modem-RF system. It enables acceleration of 5G expansion while enhancing coverage, power efficiency and performance for users.
mmWave has been deployed by major operators in the U.S. and Japan, and more than 150 worldwide have invested in it. Its features are driving 5G mmWave rollouts and 5G SA network development.
Snapdragon X65 supports:
Jeff Shamblin, Taoglas: When integrating cellular and GNSS antennas into a product, we use the following to increase isolation between the antennas:
There are techniques in which slots or other apertures can be etched or integrated into the PCB. The antennas use a ground plane to increase isolation by altering the current flow on the PCB ground layer.
Jeff Shamblin, Taoglas: It will be more accurate to simulate all PCB layers to get a precise measure of shielding effectiveness and noise immunity. When we only want to characterize antenna performance (e.g., return loss and radiation patterns), we can consider the PCB ground layer(s) to measure antenna performance accurately.
One of the differences between these two scenarios is the frequency bandwidth under consideration. Noise immunity can involve much wider frequency bandwidths when compared to the frequency response of an antenna under consideration.
Jeff Shamblin, Taoglas: Antenna placement is vital when designing antennas in a small form factor device. The antenna uses the host ground layer (PCB of the radio board) as a ground plane from which to operate.
For most IoT devices, such as smartphones and laptops, the ground layer is only one-quarter wavelength to a wavelength at sub-6 GHz frequency bands. This scenario results in a small or resonant ground plane in which antenna impedance and efficiency are affected by location on the PCB.
Good antenna placement at the start of a project will result in higher antenna gain and broader frequency bandwidth.
Anand Venkataraman, Qualcomm Technologies: 5G NR mmWave’s multi-gigabit speed and ultralow latency can elevate user experiences. This technology provides an unlimited capacity for devices, including:
Qualcomm Technologies has been working with indoor venue owners and operators to better understand 5G NR mmWave indoor performance.
Snapdragon is a product of Qualcomm Technologies, Inc. and/or its subsidiaries.