Digital Processing of the Ultrasonic Signal for Mobile Devices in the Transmission of Information

摘要

Currently, broadband wireless has largely dominated RF systems using a variety of technologies, including popular commercial protocols such as IEEE802 and Bluetooth. In this work, we consider the study of the effect of direct exposure to ultrasonic waves on an active dielectric using an ultrasound sensor. This provides several advantages over existing methods, especially to ensure safety - it is effectively blocked by most barriers and has a limited distribution range, which makes it very difficult to organize interception from outside the premises. The use of ultrasonic vibrations is one of the simplest and most effective methods for processing an ultrasonic signal. The advantage of this method is that ultrasound is not audible to the human ear, therefore, it does not have a negative mental effect on a person and by increasing the radiation power, a larger suppression area can be achieved. As a result, in the ultrasonic range, beats of two signals occur, at which a periodic change in the amplitude of the total signal occurs. The experiment uses a conventional mobile phone, which miraculously generates a difference frequency of 2 kHz from mixed ultrasonic signals with frequencies of 18 kHz and 20 kHz. The spectral conversion of an ultrasonic signal to a low frequency sound resembles the effect of the appearance of radio sound. The use of beats of ultrasonic vibrations allows you to create a simple and effective processing of an ultrasonic signal.