| 摘要 |
PURPOSE:To expand dynamic range for detecting electric field strength while securing low NF processing by forming a 1st signal path with a circuit with priority of communication quality and a 2nd signal path with a circuit with priority of wide dynamic range. CONSTITUTION:Detection signals i3-i5 extracted from post-stage amplifier circuits 33-35 except amplifier circuits 31, 32 with priority of low NF processing and high sensitivity among the amplifier circuits 31-35 of a 1st signal path 100 and detection signals i1, i2 extracted from amplifier circuits 61, 62 with priority of wide dynamic range of a 2nd signal path 200 are added and the sum is inputted to a signal intensity detection circuit 5. The circuit 5 processes the added detection signal to provide an output of the reception electric field strength detection voltage. The circuit with low NF and high sensitivity priority is adopted for the circuits 31, 32 and the circuit with wide dynamic priority is adopted for the circuits 61, 62 in this way, then the reception signal is demodulated in an excellent way and the electric field strength is detected over a wide dynamic range. |
