balanced operation the rf carrier signal does not appear in the transmitted signal u2014 all of the power is vested in the information sidebands because the rf carrier is suppressed by balancing well known methods can be used to reconstitute the rp carrier at the receiver as will be described 0050 fig2 shows a simplified block diagram of a receiver for demodulating received abpm signals in accordance with a preferred form of the invention the rf carrier is reconstituted by rectifying the signal g to produce a second harmonic i this second harmonic i is then detected by means of a phase locked loop 8 acting as a narrow band filter next the signal is divided by 2 1 scaler 9 to reproduce the original carrier signal k this technology is conventionally used to regenerate the carrier signal in the case of simple bpm the input signal g to the receiver is hard limited by limiter 6 the limited signal h is then doubled by frequency doubler 7 to produce a strong second harmonic carrier signal i a narrow bandwidth phase locked loop pll 8 detects the signal followed by a 2 1 scaling operation performed by divide by 2 circuit 9 to recover the rf carrier a 90 degree phase shifted signal l then detects the signal h in multiplier 11 the output m of the multiplier detector is a composite waveform of information and bias signals see fig3 c following the final detector a final filter 12 rejects the bias signal restoring the information signal to its proper form see fig3 b at receiver output o when the signal is finally detected through.