Design of a Wideband Surface Mountable Suspended Integrated Strip-Line Technology

This paper presents a low-loss surface mountable suspended integrated strip-line (SISL) technology. A DC-20 GHz thru transmission line and an eleventh-order generalized Chebyshev lowpass filter (LPF), with a cutoff frequency of 18 GHz, are simulated, fabricated, and measured to demonstrate the first-ever surface mountable suspended strip-line designs. Measured results of the thru line show less than 1 dB of insertion loss and greater than 10 dB of return loss across the 20 GHz bandwidth. Moreover, measured results of the LPF show less than 1 dB of insertion loss and greater than 10 dB return loss across the 18 GHz passband, as well as greater than 30 dB of suppression above 19 GHz. The proposed SMT SISL technology also has advantages of compact size, light-weight, low cost, and elimination of the extended circuit to be a multi-layer board following the trend to reduce the size, weight, power, and cost (SWaP-C).