IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 58, NO. 2, FEBRUARY 2010 403 Radio-Optical Dual-Mode Communication Modules Integrated With Planar Antennas Anatoliy O. Boryssenko, Member, IEEE, Jun Liao, Member, IEEE, Juan Zeng, Member, IEEE, Shengling Deng, Member, IEEE, Valencia M. Joyner, Member, IEEE, and Z. Rena Huang, Member, IEEE Abstract—This paper presents new results on integrated devices for radio and free-space optical dual-mode communication. Two novel hybrid packaging schemes using two different microwave printed antenna designs are presented for the integration of radio-optical front-end circuits on a planar compact printed circuit board with shared electrical and structural components. Full-wave electromagnetic (EM) simulations are presented for antenna optimization to minimize EM interference between the radio and optical circuits. A hybrid radio-optical package design is developed, prototyped, and experimentally studied using a modified quasi-Yagi antenna with split directors to form pads for opto-electronic device integration. Dual-mode link connectivity is investigated in simulations and experiments. A data rate of 2.5 Gb/s is demonstrated for the optical channel despite 15–20-dB signal coupling between the optical and microwave circuits. Index Terms—Antenna, dual-mode wireless communication, in- tegration, optical receiver, optical transmitter, packaging designs. I. INTRODUCTION T HERE IS an increasing interest in hybrid communica- tion systems to combine the advantages of radio and optical free-space signaling for future communication and network technologies with increased bandwidth, reduced power consumption and cost, high adaptability to dynamic operational environment, and other promising features [1]–[3]. Dual-modality imaging incorporating microwave and optical sensors also represents a practical interest for biomedical studies including early breast cancer detection [4]. To reach such goals, new integration and packaging techniques must be advanced to account for several orders of dimensional discrepancy between antenna geometries, measured typically in millimeters at microwaves, and characteristic sub-millimeter dimensions of the active optical components. Several hybrid Manuscript received April 15, 2009; revised September 29, 2009. First pub- lished January 19, 2010; current version published February 12, 2010. This work was supported in part by the Rensselaer Polytechnic Institute under an Internal Seed Grant, by the National Science Foundation (NSF) under Grant ECCS-0823946, and by the Collaborative Biomedical Research (CBR) Program Grant, University of Massachusetts, Amherst. A. O. Boryssenko is with the Department of Electrical and Computer En- gineering, University of Massachusetts, Amherst, MA 01003 USA (e-mail:bo- ryssen@ecs.umass.edu). J. Liao, S. Deng, and Z. R. Huang are with the Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 USA (e-mail: liaoj2@rpi.edu; dengs@rpi.edu; huangz3@rpi.edu). J. Zeng and V. M. Joyner are with the Department of Electrical and Com- puter Engineering, Tufts University, Medford, MA 02155 USA (e-mail: juan. zeng@ece.tufts.edu; vjoyner@ece.tufts.edu). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TMTT.2009.2038441 Fig. 1. Two printed antennas used for hybrid radio-optical packaging studies. (a) Quasi-Yagi. (b) Microstrip patch. All dimensions are in millimeters. integration approaches were demonstrated to solve this chal- lenging problem by employing single-module and single-chip designs [5]–[7]. Here we report results of ongoing multiuniversity research efforts in the design, development, and testing of miniaturized radio-optical transceiver modules for combined radio-optical wireless communications. The research outcome will accelerate deployment of sensor networks by providing agile and reliable connectivity with long standby time and low manufacturing cost. Two hybrid radio-optical packaging schemes are con- sidered, which are based on two versions of the microwave antennas: quasi-Yagi antenna [1], [8], [10] and microstrip patch antenna [9], as shown with their major dimensions in Fig. 1. These designs are tuned to operate around 11 GHz for a narrow- band radio link and several gigabit per second data rates for an optical link. Both designs are developed by taking advantage of the dimensional difference between the microwave antenna and optical front-end elements. Specifically, the optical elements share some physical space with microwave circuits to minimize the overall packaging area/volume and align directions of optical and microwave radiation. Both designs with quasi-Yagi antenna [see Fig. 1(a)], and microstrip patch antenna [see Fig. 1(b)], are first analyzed in numerical simulations and then designed, prototyped, and experimentally tested. Coupling from the microwave circuits to the optical trans- mitter and receiver front-ends is important in the view of 0018-9480/$26.00 © 2010 IEEE Authorized licensed use limited to: Rensselaer Polytechnic Institute. Downloaded on August 06,2010 at 20:22:41 UTC from IEEE Xplore. Restrictions apply.