| 摘要 |
<p>A receiver for amplitude modulated signals, particularly a receiver in which the amplitude of such signals is measured and a digital output produced.</p><p>A receiver is disclosed which is capable of measuring the amplitude of an input signal over an 80dBm range. The input signal is applied via a limiter (12) to a power splitter (14). First and second video detectors (16, 20) are coupled to the power splitter (14), in the case of the second video detector (20) an R.F. linear amplifier (18) is connected in the signal path to provide an overall 40dB's of gain relative to the input of the first video detector (16). Each video detector comprises a detector stage (22) whose output is connected to an amplifier chain (24, 26, 28) each amplifier in the chain having a gain of 10. The outputs of the detector stage (22) and amplifiers (24, 26, 28) are quantised and applied to a logarithmic analogue-to-digital converter (30). The outputs of the respective analogue-to-digital converters are applied to a combiner (32).</p> |
