Development of a very low-cost suspended-substrate strip-line configuration using nonconventional material

A very low-cost suspended-substrate strip-line configuration is developed using packaging foam and a very thin Cu-clad glass-epoxy laminate. The material characteristics, such as effective dielectric constant, attenuation, and loss tangent, have been determined accurately using two different transmission measurement techniques. A λ / 4-long 50 Ω transmission line is fabricated on the developed configuration, and tested successfully. The measured insertion loss is less than 0.15 dB, and the return loss is greater than 35 dB over the entire L-band.