| 摘要 |
<p>A swept frequency theft detection system for detecting different resonant circuit targets (14) which are resonant at different frequencies. The system comprises arrangements to generate swept frequency transmitter signals centered at different frequencies but which are swept in synchronism. Also provided are antennas (40, 42, 56, 58) formed by offset loops (40a, 40b, 42a, 42b), with the loops of different frequency antennas lying along different diagonal lines.</p> |
