Digitaler Echtzeit-Frequenzmesser mit räumlicher Abtastung

摘要

The meter includes a transmission line 1 terminated by a short-circuit 2. The signal whose frequency is to be measured generates a standing-wave pattern in this line in which a spatial sampling is performed by means of detectors 11 to 16; 21 to 26 which are regularly spaced over its length and which are connected to banks of spatial-frequency discriminators 31 to 33; 41 to 43 delivering in parallel the digits of a binary word characteristic of the frequency measured. Said spatial-frequency discriminators e.g. 31 have periodic frequency responses with alternate passbands and stopbands separated by transitions which are regularly distributed over the overall frequency band of the frequency meter and whose number doubles when passing from a discriminator to the next, (Figs 2, 4). The discriminators may use differential (Fig 3) or operational (Figs 5, 6) amplifiers. A pair (Fig 7) of meters with cascaded outputs may be used for increased accuracy. <IMAGE>