Complex sentence: A large amplification is required in the VSWR meter because the limit of the square law range square law, of a detector diode, the range over which the demodulated output voltage is proportional to the square of the carrier voltage on the line.
Split into simpler sentences: A large amplification is required in the VSWR meter because the limit of the square law range square law. Of a detector diode, the range over which the demodulated output voltage is proportional to the square of the carrier voltage on the line.