This work presents a design process for developing a dedicated hybrid thick-film time domain reflectometer. The design process allows for variation of the pulse generator characteristics as well as the output impedance of the unit. The unit is fabricated using standard thick-film hybrid techniques while giving consideration to problems encountered at microwave frequencies. This thesis also presents an overview of time domain reflectometry and its applications. Special emphasis is given to the problem of characterizing material dielectric constants using delay measurements.