Tiny Integrated Network Analyzer for Noninvasive Measurements of Electrically Small Antennas

Abstract

Antenna mismatch and crosstalk are recurring issues in telecommunications. For electrically small antenna systems, these are very hard to measure without affecting the radiation performance of the system and, consequently, the measurement itself. Electrically small antennas are found in many applications ranging from consumer electronics to industrial systems. We propose a radically new approach to characterize crosstalk and mismatch based on vector network analysis. By miniaturizing the network analyzer, it can be integrated in the system under test, eliminating the need for cables leaving the system. The tiny integrated network analyzer is a stand-alone Arduino-based measurement system that utilizes the transmit signal of the system under test as its reference. It features a power meter with triggering ability, on-board memory, universal serial bus, and easy extendibility with general-purpose input/output. The accuracy and repeatability of the proposed system is documented through the repeatability of the calibration. To showcase the capabilities of the system, a measurement is made on a modified smart phone with the system inside. These early results show great promise for miniaturized network analysis. With the advances in software-defined radio, we can expect much more flexible and advanced integrated network analyzers in the coming years.