GPS signal jammers block or interfere with the communication between GPS receivers and satellites by transmitting interference signals of specific frequencies, making them unable to work properly. The following are several common working modes of GPS signal jammers:

1. Noise Jamming

Principle: Transmit broadband noise signals to cover the frequency range of GPS signals (1.2GHz-1.6GHz) and drown out satellite signals.

Features: Simple and easy to implement, but may affect other devices.

2. Spoofing

Principle: Transmit false signals similar to GPS signals to mislead the receiver to calculate the wrong position or time.

Features: Highly concealed, but complex technology, requiring accurate simulation of GPS signals.

3. Pulse Jamming

Principle: Transmit high-power pulse signals to briefly interfere with GPS receivers.

Features: The interference time is short, but the effect is significant.

4. Continuous Wave Jamming

Principle: Transmit a continuous wave signal of a single frequency to interfere with the specific frequency of the GPS receiver.

Features: Highly targeted, but requires precise frequency matching.

5. Sweep Jamming

Principle: Transmit a signal with a constantly changing frequency to cover the entire frequency range of the GPS signal.

Features: Wide interference range, but complex equipment.

6. Narrowband Jamming

Principle: Interference is performed on a specific frequency of the GPS signal.

Features: Strong interference effect, but requires precise frequency matching.

7. Wideband Jamming

Principle: Transmit a broadband signal to cover the entire frequency range of the GPS signal.

Features: Wide interference range, but high power demand.

8. Smart Jamming

Principle: Dynamically adjust the jamming strategy according to the characteristics of the GPS signal.

Features: Good jamming effect, but complex technology.

Notes:

Legality: Using a GPS signal jammer may be illegal and must comply with local regulations.

Environmental impact: Jammers may affect surrounding equipment and should be used with caution.

GPS signal jammers have various working modes. Choosing the appropriate mode should be based on specific needs and environment, and attention should be paid to legality and ethical issues.