Short answer: No — and here’s why. Imagine buying a new 5G phone only to discover it uses one RF chain. What would that mean for your experience? Would the performance still feel “5G”? And is a single-antenna 5G device even allowed?
Why You Bought a 5G Phone?
One of the primary motivations for upgrading to 5G is the ability to enjoy higher throughput, faster speeds, and an enhanced user experience. But none of that is possible without one critical technology: MIMO.
MIMO: The Core of 5G Performance
MIMO improves performance by using multiple antennas on both the device and the network (massive MIMO). 3GPP Release 15 made MIMO foundational to 5G NR, not optional. It defines massive MIMO for the network and multi-antenna architectures for devices.
2×2 MIMO is the baseline for most smartphones, and many modern 5G phones include 4×4 MIMO. Even low-cost 5G devices rarely go below 2×2 MIMO, as without MIMO, essential 5G features cannot function properly. For example, AT&T clearly states the minimum expectations for 5G device design: “5G devices are required to support 4×4 MIMO by default. Under certain circumstances, 2×2 MIMO may be allowed — contact your Partner Coordinator (PC) if you believe 2×2 MIMO is required. Single-antenna implementations for NR FR1 are not permissible.”
This reinforces an industry-wide truth: A 1×1 5G device is not allowed because it cannot deliver acceptable NR performance. A single-antenna “5G” device would suffer from poor signal reliability, a significant reduction in throughput, and no support for high-order modulation or beamforming and loss of coverage in sub-6 GHz and mmWave
Why? Because 5G relies heavily on spatial diversity to overcome fading, blockage, and multipath. With one antenna, zero diversity gain, no selection of better signal paths, and deep fades, total link drops occur, and mobility exacerbates this issue further.
Why Not 8×8 MIMO in Phones?
Simple: physics won’t allow it. For sub-6 GHz, antennas require a spacing of approximately half a wavelength; at 3.5 GHz, this translates to around 4.3 cm. A smartphone cannot physically fit eight properly spaced antennas. This is why 8×8 MIMO is not used in handheld devices. For a smartphone supporting 8×8 MIMO, it is highly challenging (antenna spacing, size constraints, cost). It’s more realistic in fixed/CPE/routers.
I read one paper, in the first comment, that shows that 8×8 MIMO is technically possible in a smartphone antenna design (at least in simulation) for sub-6 GHz bands; however, it is at the simulation/academic-prototype level, not necessarily a mass-market production smartphone.
A 5G device without MIMO is not really a 5G device — neither in user experience nor in certification requirements. MIMO isn’t optional; it’s a fundamental part of achieving the performance that 5G promises.