Block diagram and operation of transmitter unit of mobile handset

Block diagram and  operation of transmitter unit of mobile handset

Block diagram  of transmitter unit of mobile handset

•  It is a low power unit operating in the frequency range of 824 to 845 MHz.
• Carrier is obtained from frequency synthesizer and applied to Phase Modulator along with the amplified voice signal.
• Modulator output is converted using a mixer to final transmitter frequency.
• Mixer output is applied to Class C amplifier.
• The final amplifier stage is to design to supply 3W to antenna.
• The automatic power control circuit controls the o/p power of the transmitter automatically, with the help of power output detector & DC amplifier.
• Transmitter output is fed to duplexer .
• Carrier input for the phase modulator & the local oscillator frequency signal for mixer are produced by frequency synthesizer. 
• Transmitter output power controlled by cell site & MTSO.
• Receiver picks up the special control signals & sends to APC that sets transmitter o/p power Level.

• Tweet
• Share
• Share
• Share
• Share