Dispersion and radiation properties of the conductor-backed coplanar waveguide (CPW) with finite ground planes are analyzed and modeled. A frequency-domain finite-difference method using the perfectly matched layer absorbing boundary condition is used as reference. Based on these results, a closed-form description is derived and implemented into an existing quasi-static CPW model. This leads to a comprehensive and efficient CPW description accounting for all relevant effects from conductor loss to high-frequency dispersion. Additionally, design rules to avoid parasitic radiation effects are given.

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The time-domain characterization of high-frequency devices with coaxial connectors requires the transfer of picosecond electrical pulses between coplanar and coaxial lines. Microwave probes are often used for this purpose. In this paper, the propagation of ultrashort electrical pulses over a microwave probe attached to a coplanar waveguide is experimentally studied by time-domain electro-optic sampling. From the experimental data, the attenuation and dispersion constants of the probe are determined up to 400 GHz. Moreover, the complex reflection and transmission coefficients of the junction between the microwave probe and the coplanar waveguide are extracted. Simple approximations are given for these quantities. These data can be used to predict the amplitude and shape of ultrashort electrical pulses after propagation over the microwave probe for arbitrary input pulses in the considered frequency range.

Many packaging concepts use via arrays fur grounding and tu eliminate parasitic modes. Such arrays rep resent periodic structures and change their behavior beyond a certain frequency. Proper design of via geometry and pitch is necessary. For this purpose, elecbomagnetic simulation data and an equivalent circuit model are presented.