All-Planar RF Integration Approach to Millimeter-Wave Wireless Front-Ends

Abstract

Recently, indoor wireless local area network (WLAN) and broadband communication systems operating at millimeter-wave frequencies have attracted much interests because they offer the advantage of high data rates. Two distinct technologies employing non radiative dielectric (NRD) guides and rectangular waveguides have been rigorously developed to efficiently achieve stringent radio-frequency (RF) system specifications [1,2]. Yoneyama et al. reported high-performance, low-loss millimeter-wave building blocks such as filters, voltage-controlled oscillators, mixers, modulators and antennas; these components can be integrated by the NRD technology. On the other hand, a single-substrate transceiver module for 76–77 GHz autonomous cruise control (ACC) radar applications was reported, where (monolithic microwave integrated circuits) MMICs and discrete devices were mounted in a multi chip module (MCM) fashion by wire-bonding and flipchip techniques. Both millimeter-wave module integration technologies are aimed for low-cost, high-volume and high-yield designs. The guiding technologies mentioned above perform well at millimeter-wave frequencies, however, some modules would require complicated analyses and mechanical fabrication processes, hence increasing the cost and complexity of the system integration efforts. For example, the well-known horn antennas are three-dimensional; thereby they need transitions to handle mode conversion and impedance matching from waveguides to planar circuits and vice versa [3]