Page 286 - Build Your Own Transistor Radios a Hobbyists Guide to High-Performance and Low-Powered Radio Circuits

FIGURE 15-27 The summation of the two multiplied signals V RF х SQ( t)

and -V RF
Adding ог combining the waveforms from Figures 15-24 and 15-26 results in the

waveform shown in Figure 15-27.
Now let's take а look at Figure 15-28, which shows the input signal VRF multiplying
thle bipolar square-wave signal SQbp(t). Note that Figures 15-27 and 15-28 аге

identical, which confirms that the multiplexer circuit in Figure 15-20 сап Ье
an,alyzed in terms to two unipolar square waves that have levels of О and: + 1. The
first unipolar square wave at Odegrees of phase is multiplied Ьу ап input signal,
and the other unipolar square wave at 180 degrees of phase is multiplied Ьу ап
inverse phase input signal, which when the two multiplied outputs аге summed will
provide а signal equivalent to the input signal, multiplying а bipolar square-wave

signal that has levels of -1 and +1.