| 摘要 |
A rectifier, preferably a bridge rectifier, is connected in series between a radio frequency (RF) signal generator and audio signal generator, and an antenna included in an RF signal transmitting circuit for rectifying the signal generated by the transmitting circuit before transmission. In the case of an amplitude modulation (AM) transmitting circuit, relatively low percentage modulation causes the rectifier to operate in a linear range and results in relative intensification of the power in the sidebands of the AM signal, whereby the ratio of the sideband power to the carrier power is increased which means that a relatively greater amount of power is applied to transmission of the message-bearing sidebands as compared to the carrier than in conventional AM transmitting circuits. Furthermore, relatively high percentage modulation causes the rectifier to operate in a nonlinear range and results in generation of a detectable angle modulation equivalent signal which has the advantage over conventional angle modulation transmitting circuits that a carrier is not transmitted when there is no modulating signal.
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