ANALYSIS OF THE CHARACTERISTICS OF A LOW-POWER FILTER ON TRANSIENT INDUCTANCE ANALOGS AS AN ALTERNATIVE TO FILTERS ON COUPLED RESONATORS

Abstract

With the increase in the number of signals in all spectrums and frequency ranges of information transmission, the problem of congestion of the entire transmission band is acute. Accordingly, there is a need to filter signals and select useful ones in order to ensure the effective operation of the radio engineering system. One of the areas of application of transistor analogs of inductance is their use to replace passive inductances in LC filters. This application is due to the fact that the transistor analogue of the inductance, as an active element, has a rather small sensitivity to the spread of the parameters of the passive elements of the circuit, compared to the sensitivity of ordinary LC filters. When using active RC filters based on transistor analogues of inductance, there is also the possibility of matching the resistances of the power source and the load in the frequency band, which further reduces the sensitivity of the active filter.

The article analyzes the main characteristics of low-power bandpass filters. Filters on coupled resonators are considered and the use of transistor analogs of inductance as their alternative is proposed. The change in the main parameters of filter components when replacing the main element with a transistor was studied. The main aspects are characterized and the coefficient of the pre-filter using a transistor analogue of the inductance is investigated. The mode of operation of a small signal transistor and its main conditions are considered. Analyzed conditions that must be followed when choosing an active element. The dependence of operation and parameters of transistors on DC power supply, its stability and uninterrupted power supply is given. The possibility of using an asymmetric strip transmission line with dielectric filling is analyzed.