We present experimental results for an integrated coplanar phase shifter based on varactor diodes fabricated using a silicon on glass process. A differential phase shift of 180 degrees is obtained at 50 GHz with the dc bias voltage varied between 2.1 and 15 volts. The return loss of the phase shifter is below 15 db. The insertion loss strongly depends on the dc bias voltage applied, but is below 14 db in the bias range of interest.@en