Hemispherical Angular Power Mapping of Installed mmWave Radar Modules Under Realistic Deployment Constraints

TL;DR

This work addresses the challenge of validating angular radiation from mmWave radar modules when installed in host platforms, where traditional antenna test ranges are infeasible. It introduces an in-situ hemispherical angular power mapping approach that samples the accessible half-space around a stationary DUT using amplitude-only measurements and a geometry-calibrated probe-positioning workflow. The method’s core enables deployment-aware validation with a transform $T_{\mathrm{final}} = T_{\mathrm{base}} \times T(\phi,\theta,r) \times T_{\mathrm{offset}}$ and demonstrates proof-of-concept measurements at $58$–$63$ GHz showing MAE ~ $1$–$2$ dB against full-wave simulations across $r=4$–$15$ cm. The technique provides a practical tool for field-of-view verification, packaging impact assessment, and installation troubleshooting of embedded mmWave transmitters in semi-controlled environments.

Abstract

Characterizing the angular radiation behavior of installed millimeter-wave (mmWave) radar modules is increasingly important in practical sensing platforms, where packaging, mounting hardware, and nearby structures can significantly alter the effective emission profile. However, once a device is embedded in its host environment, conventional chamber- and turntable-based antenna measurements are often impractical. This paper presents a hemispherical angular received-power mapping methodology for in-situ EM validation of installed mmWave modules under realistic deployment constraints. The approach samples the accessible half-space around a stationary device-under-test by placing a calibrated receiving probe at prescribed (phi, theta, r) locations using geometry-consistent positioning and quasi-static acquisition. Amplitude-only received-power is recorded using standard RF instrumentation to generate hemispherical angular power maps that capture installation-dependent radiation characteristics. Proof-of-concept measurements on a 60-GHz radar module demonstrate repeatable hemi-spherical mapping with angular trends in good agreement with full-wave simulation, supporting practical on-site characterization of embedded mmWave transmitters.

Figures (2)

• Figure 1: Semi-anechoic hemispherical mapping setup for in-situ characterization of an installed mmWave radar module, including automated probe positioning, stationary DUT, absorber-lined workspace, and spectrum-analyzer-based received-power logging for angular power map generation.
• Figure 2: Comparison of normalized received-power in simulation and measurement at the workspace boundary. (a)–(c) correspond to $r=8$ cm with $15^\circ$ sampling for $\phi$-plane cuts at $0^\circ$, $180^\circ$, and $300^\circ$, and (d)–(f) correspond to $r=5$ cm with $10^\circ$ sampling for $\phi$-plane cuts at $0^\circ$, $100^\circ$, and $300^\circ$.