| 摘要 |
A dual function field strength sensor (10), in accordance with an inventive arrangement, comprises: a alternating current magnetic field detection circuit (30); a first antenna (31) for the AC magnetic field detection circuit; a radio frequency (RF) field detection circuit (20); a second antenna (21) for the RF field detection circuit (20); an amplifier and filter stage (24, 25, 35, 36) for processing output signals from any selected one of the detection circuits; a switch (12) for selecting which one of the output signals is processed by the amplifier and filter stage; an output stage responsive to the amplifier and filter stage and driving at least one field strength indicating device (50) operable for both AC magnetic fields and RF fields detected by the detection circuits. The second antenna comprises a flat conductive path (26) partially encircling and separated from other components on a printed circuit board (90), the path having a dipole configuration and including a serpentine section (27). |
