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A full-wave moment method implementation, using a combination of spatial and spectral domains, is developed for the analysis of quasi-optical systems. An electric field dyadic Green's function, including resonant and nonresonant terms corresponding to coupling from modal and nonmodal fields, is employed in a Galerkin routine. The dyadic Green's function is derived by separately considering paraxial and nonparaxial fields and is much easier to develop than a mixed, scalar and vector, potential Green's function. The driving point impedance of several antenna elements in a quasi-optical open cavity resonator and a 3 x 3 grid in free space are computed and compared with measurements.

The system concept and data transmission experiments for a mobile broad-band communication system at 60 GHz are presented in this paper. Dense wavelength division multiplexing (DWDM) is advantageously applied for simultaneous electrooptical upconversion of all optical channels carrying individual intermediate-frequency signals by means of a single external modulator. Thus, simple, but flexible, millimetric signal generation is obtained. Using this concept, data transmission experiments at 60 GHz have been carried out. Furthermore, the transponder noise performance is analyzed. Results of coded and uncoded 512-carrier orthogonal frequency division multiplex transmission with 50-Mb/s (subcarrier modulation quaternary phase-shift keying), 100 Mb/s (subcarrier modulation 16-quadrature amplitude modulation) as well as single-carrier modulation at 156 Mb/s utilizing three operational DWDM channels are presented. Uplink and downlink transmission has been realized. The significant performance improvement due to the application of coding is demonstrated in some experiments and line-of-sight transmission is compared to nonline-of-sight transmission. Low bit error rates, employing realistic air link conditions, have been obtained in all experiments. Index Terms--Electrooptical upconversion, millimeter-wave radio communication, millimeter-wave generation, remote oscillator generation, 60-GHz transmission.

This paper describes the combined effects of laser chirp, electrooptical mixing, dispersive fiber transmission, and photodetection on the nonlinear signal properties of the electrooptically generated millimeter-wave signal (60 GHz). Analytical expressions describing the complex currents of fundamental and higher order products are provided for the case of single-tone modulation as well as for two-tone modulation, respectively. Examples will be considered including the nonlinear amplitude response (output power at millimeter-wave range versus input power at IF), the nonlinear phase response (relative output phase at millimeter-wave range versus input power at IF), the input related 1-dB gain compression condition, the amplitude response of third- and fifth-order intermodulation products, as well as the input related intercept points for the latter signals. The model developed performed well, even under moderate to large signal conditions, and very good agreement has been achieved between theory and experiment. Index Terms--Dispersive optical channel propagation, electrooptical mixing, millimeter-wave communication, optical transmitter chirp.