Miniaturisation in E-Plane Technology
In a simple and cheap way, a planar full-band matching technique allows for miniaturisation of E-plane components. such as corners. shifts. T junctions. Magic Tees. cross-over and quadrature directional couplers a.o. A finline taper has been made half the length of the shortest computer optimized one, having similar performance. A transition to suspended stripline offers possibilities for this line instead of the finline. Although realised for X-band, scaling down to mm waves is our aim as well as application for devices. Additional technical details will be given at the oral presentation.
Synthesis of Optimum Finline Tapers Using Dispersion Formulas for Arbitrary Slot Widths and Locations
The theory of TEM matching sections has been modified so that it can be applied to finline tapers. A step-by-step procedure is given to calculate the taper contour for a given maximum VSWR. The taper is optimum in the sense that its length is the shortest possible for the required VSWR. To achieve fast convergence, a transversal resonance method was developed to calculate finline dispersion, which is valid for arbitrary slot widths and slot locations. The finline can be unilateral as well as bilateral, and the slot may be off-centered. The dispersion data are compared with values found in the literature, and the calculated taper performance with the authors' own measurements, both showing good agreement.
An analytical approach to the design of electrodes in high-power, fast-transverse-flow CO2 lasers
Abstract Usually, the design of the electrodes of fast-transverse-flow CO 2 lasers relies more on experimental data than on theoretical analysis. Traditional systems sustain a stable, high-power discharge but the current distribution generates a peaked, non-uniform small-signal-gain pattern. We present a theoretical model suitable for the design of electrodes that achieves a quasi uniform gain distribution. The analysis, based on a two-temperature model and the gas-transport equations, computes the electron density that supports a flat gain pattern. Combining the desired electron density with the electron-balance equations, the model determines the required electric field. The results were used to design a new set of electrodes for a home-made fast transverse flow CO 2 laser. A stable, large volume discharge ( 4 × 8 × 90 cm 3 ) with very good uniformity was obtained. The resulting gain distribution was registered in a bi-dimensional map. The peak gain rose from 1.2 m - 1 , attained with the old electrode set, to 1.6 m - 1 with the new one and the gain showed a homogeneous profile.