System and method for automatically adjusting channel output level of superheterodyne receiving analytical instrument

Abstract

The invention discloses a system and method for automatically adjusting channel output level of a superheterodyne receiving analytical instrument. The system for automatically adjusting the channel output level of the superheterodyne receiving analytical instrument comprises a radio frequency channel, a medium frequency channel, an analog-to-digital converter, an FPGA / DSP, a scanning controller, a CPU, a timer, a channel output level controller, a counter, a coupler, a power detection unit and an interrupt controller. Compared with the prior art, due to the fact that the channel output level controller is used in cooperation with the coupler, the power detection unit, the timer, the counter and the interrupt controller to achieve the function of automatic control over the channel output level in the process of scanning, the purpose of protecting the superheterodyne receiving analytical instrument and the purpose of improving signal measurement accuracy are achieved. In addition, the number of times of interference of the CPU to the scanning process is greatly reduced, the measuring time is reduced, and smoothness of integral operation of the superheterodyne receiving analytical instrument is improved.

Description

technical field [0001] The invention relates to an automatic adjustment system for the channel output level of a superheterodyne receiving analysis instrument and an automatic adjustment method for the channel output level. Background technique [0002] When using a superheterodyne receiving analysis instrument to measure an unknown electromagnetic environment, there may be some high-power signals in the unknown electromagnetic environment. The light ones of these high-power signals will affect the nonlinear devices in the superheterodyne receiving analysis instrument, resulting in inaccurate measurement. It will damage those power vulnerable parts and cause equipment failure. How to control the output level of the channel to protect the superheterodyne receiving analysis instrument and improve the measurement accuracy of high-power signals has become an important research topic. [0003] When measuring unknown signals, the superheterodyne receiving analysis instrument shou...

AI Technical Summary

Problems solved by technology

[0006] (1) The disadvantage of changing the output level of the channel by the method of manual setting by the user is that the control speed is slow, and it is necessary to judge which part of the superheterodyne receiving analysis instrument is overloaded, and the operator is required to have rich experience. heavy workload;

[0007] (2) The disadvantage of using the host program to participate in the change of channel gain is that the host program needs to participate in channel power detection, hardware control of attenuators and amplifiers, scanning parameter settings, and digital-to-analog converter control at each measurement frequency point. As a result, the control time is greatly increased and the measurement speed is slowed down. In addition, the high CPU usage will affect the data processing, display refresh and other processes, further slowing down the measurement speed;

[0008] (3) The disadvantage of using the intermediate frequency automatic gain method to change the channel output level is that the automatic gain method cannot control the RF channel gain and does not participate in the scan timing control of the whole machine, and the scope of action is limited

[0024] Through the adjustment method of the output level of the above channels, it can be found that the CPU needs to participate in the scanning process at any time, which greatly affects the scanning speed.

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