Portable field strength measuring instrument of DMB

Abstract

The invention relates to a portable field strength measuring instrument of digital multimedia broadcasting (DMB). The portable field strength measuring instrument is composed of a signal interface, afilter, a multi-level logarithmic amplifier, a microcontroller and a USB interface. The input terminal of the signal interface is connected to a DMB device and the signal interface is used for receiving DMB broadcast transmitting signals. The input terminal of the filter is connected to the output terminal of the signal interface to filter an interference signal among the received DMB broadcast transmitting signals; and the output terminal of the filter is connected to the input terminal of the multi-level logarithmic amplifier to convert the DMB broadcast transmitting signals from radio-frequency signals to voltage signals. The input terminal of the microcontroller is connected to the output terminal of the multi-level logarithmic amplifier to carry out data processing on the voltage signals; and the microcontroller carries out data outputting through the USB interface and the field strength measuring instrument provides power through the USB interface. Therefore, the defects of complicated structure, high price, large weight and large volume, and low portability of the existing field strength instrument are overcome effectively; and the field strengths of the DMB broadcast transmitting signals in a range from -65dBm to 5dBm can be measured accurately.

Description

technical field [0001] The invention belongs to the technical field of field strength detection equipment and relates to a DMB portable field strength measuring instrument. Background technique [0002] The strength of the field strength is an important indicator reflecting the status of the broadcasting signal. With the development of technology, the field strength measurement is gradually automated, which shortens the measurement time and realizes the mobile measurement of field strength. [0003] Most of the existing methods for measuring the field strength of broadcast transmission signals use spectrum analyzers or special field strength meters for testing. Spectrum analyzers have accurate test results and good versatility, but are bulky and expensive. The special field strength meter uses the antenna to receive the broadcast transmission signal, and then transmits it to the receiver to obtain the value. The receiver models mainly used are: IC-R75, IC-R8500 and so on....

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