Pico-second time domain reflectometry response of a microstripline embedded in various liquids

B.R. Sharma1, S.C. Mehrotra1
1Department of Computer Science and Information Technology, Aurangabad, India

Tóm tắt

A microstripline having 50 ohms characteristic impedance has been delineated on PCB type FR-4 board material, by using standard three layer dry film lamination and chemical photo-etching technology. The dielectric constant and dissipation factor for FR-4 substrate material is 4.6 and 0.018 at 1 MHz respectively. The fringing fields arising from free end of a microstripline have been employed to observe its free-end-dip liquid response. The microstripline has been vertically dipped in various liquids at different successive lengths. The response due to 40 pico second rise time pulse from free-end-dip of a microstripline in a liquid is observed on the TDR equipment in reflection mode at room temperature. The response waveform obtained is similar to the conventional co-axial transmission line connected to precision SMA cell containing liquid. The data analysis is carried out by standard Fourier transformation techniques. The microstripline of suitable length embedded in a liquid can be used as substitute to the SMA cell to determine the dielectric properties of various liquids.

Từ khóa

#Reflectometry #Microstrip #Liquids #Dielectric materials #Chemical technology #Impedance #Optical films #Lamination #Dielectric constant #Dielectric substrates

Tài liệu tham khảo

edwards, 1981, Foundations of Microstrip Circuit Design 10.1109/EUMA.1975.332206 samulon, 1951, Spectrum analysis of transient curves Proc IRE 39, 175 shannon, 1949, Communication in the presence of noise Proc IRE, 37 10.1080/02564602.2000.11416927 1995, HP54753A and HP54754A TDR plug-in modules user's and programmers guides USA cole, 1989, J Appl Phys, 66, 10.1063/1.343499 10.1021/je980118j