Antenna-First for IoT: Reversing the
Design Stack to Unlock Reliable Connectivity

By: Eric Jo, Ph.D.

Internet of Things (IoT) deployments often succeed or fail at the edge, where the realities of physics, packaging, and environmental noise determine whether a device connects, stays connected, and delivers reliable data. Over the past decade, major investments in network infrastructure, semiconductors, and cloud platforms have accelerated IoT adoption. Yet, persistent challenges—such as dead zones, intermittent telemetry, battery drain, and solutions that work in the lab but fail in the field—still plague the industry. These challenges highlight a critical oversight: the antenna system is too often treated as an afterthought rather than a foundational architectural constraint.

This article advocates for an "antenna-first" approach, elevating the antenna system (antenna, ground, enclosure, and placement) to a primary design driver. Industry analysis consistently shows that antenna performance can account for up to 40 percent of overall wireless connectivity outcomes, underscoring its foundational role in the link budget and, by extension, in IoT reliability. By reversing the traditional design sequence and prioritizing the antenna-based radiating system, this paper outlines a path to more robust, scalable, and future-proof IoT deployments.

The New Reality: IoT Is Constrained, Multi-Radio, and Antenna-Hostile

Modern connected devices are increasingly complex, often integrating multiple radios—cellular, Wi-Fi, Bluetooth, GNSS, NFC, and more—within compact, tightly packaged enclosures. It is not uncommon for today's IoT products to incorporate six, eight, or even far more antennas (for example, for high-order Multiple-Input Multiple-Output (MIMO) system devices) to meet diverse connectivity requirements. This trend mirrors the evolution of smartphones, but with even harsher constraints on volume, placement, and materials.

The core challenge is not a lack of antenna expertise, but the inherently hostile conditions imposed by many IoT form factors:

• Extremely limited internal volumes and tightly defined keep-out regions
• Prevalence of metal, carbon-loaded plastics, and other lossy materials
• Proximity to noisy components such as converters and high-speed digital circuits
• Mechanical constraints from batteries, motors, and moving parts
• Multiple antennas packed closely, increasing the risk of coupling and interference

In such environments, antenna performance can be reduced due to size constraints, noise, and negative coupling effects, resulting in overall system performance reduction.

The "Antennas Last" Pitfall: A Recipe for Field Failures

A common development pattern in IoT locks industrial design and internal component placement early, relegating antenna design to a late-stage consideration. This sequence often leaves little usable space for antennas, forcing them into suboptimal locations near noise sources or too close to each other, resulting in interference, detuning, and compromised connectivity.

An antenna-first methodology inverts this process:

1. Define the wireless mission (bands, MIMO order, coexistence, environment, orientation, Over-the-air (OTA) constraints, battery budget)
2. Architect the radiating system first (antenna geometry, ground strategy, antenna isolation)
3. Design the default product structures (enclosure, PCB/component placement, cables/connectors) while monitoring RF radiation performance
4. Design the rest of the device around the electromagnetic requirements to preserve RF integrity

This approach mirrors best practices from other high-consequence engineering disciplines, where core constraints are designed in from the start rather than patched in as afterthoughts.

Antenna Performance: The True Driver of Link Budget

Wireless performance is frequently framed as a network or infrastructure issue, but device-side RF design often becomes the bottleneck—even when back-end infrastructure is world-class. Antenna-related parameters are central to the link budget, and poor antenna performance can negate investments in other parts of the system.

Key metrics such as antenna gain and efficiency directly determine effective radiated power, receiver sensitivity, and overall link margin. For example, a 3 dB improvement in total radiated power (TRP) equates to a doubling of radiated output—a step change, not a minor tweak. Industry standards such as TRP capture real-world radiated conditions, providing a more accurate picture than benchtop measurements alone.

The Core Failure Mode in Compact Multi-Antenna Devices: Self-Interference

The hardest antenna challenges in IoT stem from the proliferation of co-located radios and antennas within tight physical confines. Surface currents and electromagnetic