TABLE OF CONTENTS In [1], the design of a broadband thin film signal sampler is described using slot lines to generate balanced sampling pulses with opposite polarity. Equal amplitudes of balanced sampling pulses are essential because good decoupling is needed to keep the gate pulse transients off the signal line. In [2, 3], a balanced avalanche discharging pulse generator was used with two coupled microstrip lines as electrical charge storage. Experience had shown that the same amplitude of the generated pulses only could be obtained after additional tuning of the load impedances. Such difficulties were not observed with sampling pulse generation using a microstrip-slot line combination. Therefore, some basic experimental results are described in this Appendix.
Slot lines can simply be incorporated in microstrip circuits by etching the slot line circuit in the ground plane of the microstrip circuit. Figure C.1 shows a short-circuited slot line of length l and slot width s, positioned perpendicular and symmetrical to a microstrip drive line. The microstrip line is terminated in its matched load, and stimulated by an electrical pulse of 47V peak value, 1.7 ns pulse width (FWHM), and 440 ps rise-time. A miniature, semi-rigid coaxial cable is placed at the center of the short-circuited slot line and used for signal detection.
In Figure C.2, the electric and magnetic field distribution both in the microstrip and slot line are illustrated to explain the coupling of the microstrip and slot line mode. This...
