Slot-Coupled Millimeter-Wave Dielectric Resonator Antenna for High-Efficiency Monolithic Integration

A readily mass-producible, flip-chip assembled, and slot-coupled III-V compound semiconductor dielectric resonator antenna operating in the millimeter-wave spectrum has been fabricated and characterized. The antenna has a 6.1% relative bandwidth, deduced from its 10 dB return loss over 58.8-62.5 GHz, located around the resonance at 60.5 GHz. Gating in the delay-domain alleviated the analysis of the complex response from the measured structure. The radiation efficiency is better than -0.1 dB in simulations fed from the on-chip coupling-structure, but reduced by 3.7 dB insertion loss through the measurement assembly feed. Antenna gain measurements show distortion in relation to the simulated pattern, which has a maximum gain of 6 dBi, mainly caused by interference from the electrically large connector used in the assembly. Mode degeneration in the utilized quadratic-footprint resonator was not seen to influence the performance of the antenna. The antenna is intended for on-chip integration and the fabrication technology allows scaling of the operation frequency over the complete millimeter-wave spectrum.

I. Introduction

There is an increasing interest in exploring the millimeter-wave (mmW) spectrum, 30–300 GHz, for various wideband applications, including short-range radar [1] and Gbit/s wireless communication [2]. While maintaining a high efficiency in these systems, it is challenging to assemble antennas with monolithic microwave integrated circuit (MMIC) radio front-ends via wire-bonded interfaces or connectors. The solution is to flip-chip (FC) assemble a multichip module (MCM) and use on-chip integration of efficient antennas and MMICs [3]. This results in reduced guiding and mismatch losses, but also allows high-precision fabrication techniques. Highly integrated antennas may be codesigned with active circuitry, allowing arbitrarily designed feed lines in between components, including direct integration.