## 4 Conclusions  
This paper presented a design of a new self-balancing AC component power amplifier with a minimum output DC component level (during operation both under and without load), which was intended for application in the launcher automation control circuit of a surface-to-air missile system. The amplifier has been designed using semiconductor technology based on a complementary MOSFET transistor pair. The system has been constructed and tested under laboratory conditions. The device operates steadily and continuously throughout the entire range of the assumed signal processing band, with a sufficiently broad reserve of the frequency bandwidth. The topology of the system ensures very good phase characteristics of the amplifier over a broad band of processed LF signals and low DPRs at a high signal-to-noise ratio. The proposed amplifier correctly maintains a minimum DC component output level regardless of (a) temporal and temperature-related load resistance changes; (b) changes in the load resistance character in terms of process LF signals; (c) changes to the LF control signal; and (d) idle current fluctuations resulting from supply voltage changes over time. The system's design does not include any additional modules interfering with the LF circuit of the amplifier, such as, e.g., external comparators correcting the output offset voltage level. Moreover, unlike typical design solutions, system fine-tuning takes place without the need to determine the minimum offset voltage level using an additional compensating potentiometer. DC operating conditions for nonlinear output elements are  
Figure 15: System response to supply voltage spikes for: (**a**) 140/9140; (**b**) 140/9240; (**c**) 240/9140; and (**d**) 240/9240 transistor pair. determined by setting the required DC biasing voltage value for the base of the transistors controlling the voltage stage. The advantages of the proposed system include the following:  
* Eliminating tube technology, which is subject to relatively rapid aging;
* Reduced power consumption owing to a significant reduction in supply voltage;
* Eliminating power supply filter chokes and thus simplifying the power supply system;
* Improved stability of electrical parameters by eliminating transformers that adapt the tube system to load or the next stage of the analog signal processing channel;
* Reducing heat emission, thus limiting the impact of high temperatures on the operation of other electronic components and adjacent function blocks;
* Significant simplification of system topology through improved operational indicators; and
* Significant reduction of the geometric and mass parameters of the device relative to the original tube system. In the longer term, the development of the proposed device into a dedicated integrated ASIC module is being considered. In civilian solutions, the application of such an amplifier would be possible, e.g., in robotic and automated systems in Manufacture 4.0, where due to higher system requirements and the use of increasingly complex communication protocols, stringent signal processing conditions are required [24; 25]. It is worth noting that preliminary tests of the LF amplifier circuit presented herein coupled with other types of transistors indicated a possibility to further reduce the voltage of the output DC component while increasing the power in new versions of devices based on the application scheme. These considerations will be the subject of a subsequent publication. Conceptualization, P.Z. and W.B. ; methodology, W.B. ; software, P.Z. ; validation, P.Z. and W.B. ; formal analysis, P.Z. ; investigation, P.Z. ; resources, P.Z. ; data curation, P.Z. ; writing--original draft preparation, P.Z. and W.B. ; writing--review and editing, W.B. ; visualization, W.B. ; supervision, W.B. ; project administration, W.B. ; funding acquisition, W.B. All authors have read and agreed to the published version of the manuscript. This work was financed by Military University of Technology under research project UGB 22-894/2021. Not applicable.