In a network employing code division multiplex access, a distortion compensation amplifying apparatus is provided which is capable of making quick response to carry out the distortion compensation with high accuracy even if the signal power to be inputted thereto varies rapidly. The flowable oxide, which is preferably very thin over the electrodes to minimize loss of sensitivity, provides a substantially planar upper surface, so that passivation formed on the flowable oxide is also substantially planar. The inner portion is comprised of a plurality of interleaved layers of high modulus cross-plied fibers embedded in resin.