Study of transmission line performance on through silicon interposer

The high frequency performance of different types of transmission line structures (including microstrip line, coplanar waveguide, grounded coplanar waveguide and differential coplanar waveguide) fabricated on through silicon interposer (TSI) is studied and characterized experimentally up to 40 GHz in this paper. Design considerations and tradeoffs are discussed in order to realize low loss, high bandwidth interconnects on TSI for radio frequency and/or millimeter wave system integration. Experimental results reveal that all the designed transmission line structures have insertion loss of less than 0.56 dB/mm for frequencies up to 40 GHz. Good impedance matching over broad frequency range (till 40 GHz) is also achieved with return loss of greater than 15 dB. Additionally, for the differential coplanar waveguide structure, high isolation of more than 27 dB for frequencies up to 40 GHz is observed between the differential and common mode conversion.