Design and Experimental Validation of Automated Millimeter-Wave phased Array Antenna-in-Package (AiP) Experimental Platform

Abstract

Antenna-in-package (AiP) technology has been a main design scheme of millimeter-wave (mmWave) phased array antennas for 5G communications. The beamforming pattern of mmWave phased array AiP is steered by controlling the amplitude and phase excitations of AiP elements. It would be helpful to evaluate the control accuracy of complex excitations and to reliably calibrate mmWave AiP. However, these tasks are not trivial and time-consuming in practice, especially when the number of AiP elements is large. To address this problem, this paper presents an efficient and automated mmWave phased array experimental platform. To reduce measurement time, a control software is developed to automatically control the AiP and measurement instruments simultaneously. This experimental platform has flexible gain and phase control of AiP element excitations, and customized measurements in an automated and efficient way can be realized. The effectiveness of the experimental platform is demonstrated by several measurement campaigns, where control accuracy, array calibration, and beam steering for mmWave phased array AiP are extensively investigated.

Over-the-Air Array Calibration of mmWave Phased Array in Beam-Steering Mode Based on Measured Complex Signals

“…A 4 × 4 mmWave phased array AiP operating from 26.5 GHz to 29.5 GHz was utilized in the experimental campaign. The AiP integrates four AWMF-0158 chips with 16 singlepolarized patch antennas [32]. The patch element spacing is 5.45 mm (i.e.…”

“…The S-parameters between the mmWave AiP antenna feed and the probe antenna feed were recorded at 28 GHz for each complex excitation setting for the AiP, with AiP operating in receive (Rx) mode. As discussed, the developed mmWave phased AiP experimental platform offers complex excitation coefficient control of individual AiP elements, thereby enabling both the REV method measurement and the conventional beam-steering operation in an automated manner [32].…”

An Improved Complex Signal-Based Calibration Method for Beam-Steering Phased Array

“…When ψ p and θ m are small, the i-th virtual beam direction ψi in (11) can be approximated according to (6), ( 8) and (10):…”

“…The validation measurements were performed in a standard CATR setup, where a 4×4 mmWave phased array antenna-inpackage (AiP) platform detailed in [6] and [13] was employed as the DUT. As shown in Fig.…”

“…In the industry, on-off is often done in the near-field with the help of a scanner [12]. However, on-off measurements might not truthfully reflect the states of the array elements in their default all-on mode, especially for mmWave phased arrays [6]. In all-on calibration measurements, all elements radiate simultaneously while we can tune the phase excitation for individual array elements.…”