Working Principle of a Walkie-Talkie

The working principle of a walkie-talkie is mainly based on radio communication technology, utilizing the transmission and reception of radio signals to achieve voice communication. Its working process can be divided into the following parts:

Sending Part:

• When the user presses the "transmit" button on the walkie-talkie, the microphone converts the sound signals into electrical signals.
• These electrical signals are used by the phase-locked loop and voltage-controlled oscillator (VCO) to generate a radio frequency (RF) carrier signal.
• The signal is then buffered, amplified, excited, and power-amplified to produce the required RF power.
  -Finally, the signal passes through a low-pass filter in the antenna to suppress harmonic components and is transmitted through the antenna.

Receiving Part:

• The receiving walkie-talkie receives the radio signal from the transmitting end via the antenna.
• The receiving section typically uses a double-conversion superheterodyne method to demodulate and amplify the received RF signal.
• The demodulated audio signal is then played through the speaker, enabling voice reception.

Modulation and Demodulation:

• At the transmitting end, after the microphone converts the sound signals into electrical signals, they are converted into radio signals by the modulator.
• At the receiving end, the received radio signals are demodulated back into the original electrical signals and then converted into sound signals.

Signaling Processing:

• The walkie-talkie also includes a signaling processing section that handles control signals and synchronization signals.

In summary, a walkie-talkie converts sound signals into electrical signals through a microphone, then amplifies and modulates them in the transmission section before transmitting them via the antenna. The receiving end receives these signals through the antenna, and after demodulation and amplification, restores them to sound signals, thus enabling two-way communication.