UHF transmitter module CS901 composed of SAW

Relevant key device information applied in this article: 3EM 8050, as shown in the figure, is an ultra-high frequency transmitter module composed of SAW, and the circuit model is CS901. It is based on the basic circuit and adds a modulation tube VT2 and a power supply filter circuit. Capacitors C5~C7 and R3 form a power filter circuit to prevent power interference and improve the stability of the circuit. VT2 and R2 form a modulation circuit and are connected to the emitter of the oscillation transmitter VT1. The data signal is input from the Vi terminal, and through the control of VT2, the digital modulation of the transmitted signal is completed. The transmitting carrier frequency of this circuit is equal to the resonant frequency of the SAW, which is 315MHz.