| 摘要 |
PURPOSE:To detect simply a reception electric field level at a mobile station by providing a comparator circuit, a sampling circuit, a counter and a reset circuit to discriminate the rate where an input analog signal exceeds a reference level or does not exceed during a prescribed period. CONSTITUTION:When an analog reception level (a) applied to a terminal 1 is fluctuated, a reference level (b) applied to a terminal 2 and the level (a) are compared (B). The result of comparison is ANDed at an AND circuit A with a sampling clock pulse (c) applied from an input terminal 3 and a pulse train (d) is outputted. The pulse train (d) is counted by a counter C, which is reset at a prescribed period by a timer input (e) from a terminal 4. The counter C has count contents of 4 bits in this case and counts at least 8 pulses, then ''1'' is set to the most significant bit in four bits. |
