摘要 |
<p>Apparatus for preventing the normal operation of a cellular mobile telephone comprising, frequency generating means (4) operable to generate an electrical signal at a predetermined frequency, sweep control means (1, 2, 3) operable to cause the frequency of the signal generated by the frequency generating means (4) to sweep at a predetermined rate across a predetermined bandwidth, amplifier means (6) for amplifying the electrical signal and antenna means (8) for receiving the output of the amplifier means (6) and for radiating the received signal.</p> |