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Research Article
Comparative Performance Evaluation of Conventional and Tuned Single-Stage Common-Emitter Transistor Amplifiers Using Multisim 11.0
Yusuf Abdullahi*
,
Ismail Garba Saidu,
Muhammad Bello Abdullahi,
Kabir Ahmed Dabai,
Buhari Bello Sahabi,
Aisha Aminu Mode
Issue:
Volume 14, Issue 5, October 2026
Pages:
211-222
Received:
29 July 2026
Accepted:
10 August 2026
Published:
9 September 2026
Abstract: The frequency response of transistor amplifiers is a key performance characteristic that determines their suitability for broadband and frequency-selective applications. This study comparatively evaluates the performance of a conventional single-stage common-emitter transistor amplifier and a tuned single-stage common-emitter transistor amplifier using NI Multisim 11.0. Both amplifier configurations were designed and simulated under identical operating conditions using a 2N2222A NPN transistor, a 12 V supply, identical biasing networks, and the same passive components. The only design difference was the replacement of the collector resistor in the conventional amplifier with a parallel LC resonant circuit in the tuned amplifier. The frequency response of both amplifiers was evaluated over the frequency range of 10 Hz to 100 MHz, and the voltage gains were calculated from the simulated output waveforms and expressed in decibels (dB). The results showed that the conventional amplifier maintained a nearly constant mid-band gain of approximately 54 dB over a wide frequency range, demonstrating excellent broadband performance. In contrast, the tuned amplifier produced a maximum gain of approximately 72.04 dB at its designed resonant frequency of 1 kHz, but exhibited a much narrower bandwidth due to its frequency-selective characteristics. The comparative analysis confirms that the conventional amplifier is better suited for broadband signal amplification, whereas the tuned amplifier is more appropriate for narrow-band and radio-frequency applications requiring high gain at a specific frequency. These findings provide useful guidance for selecting suitable transistor amplifier configurations for broadband and frequency-selective electronic and communication applications.
Abstract: The frequency response of transistor amplifiers is a key performance characteristic that determines their suitability for broadband and frequency-selective applications. This study comparatively evaluates the performance of a conventional single-stage common-emitter transistor amplifier and a tuned single-stage common-emitter transistor amplifier u...
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Research Article
Design of A Post Quantum Key Encapsulation Mechanism for Consumer Electronics Using Ring Learning with Layered Errors
Fagbohunmi Griffin Siji*
Issue:
Volume 14, Issue 5, October 2026
Pages:
223-238
Received:
13 June 2026
Accepted:
8 July 2026
Published:
29 October 2026
Abstract: The rise in technical features and capabilities of consumer electronics (CSE) devices ranging from smartphones, high fidelity (Hifi) radio systems, MP radio sets and IoT-enabled smart devices, have created new possibilities about their use and applications. You tube files can now be downloaded on smartphones and played directly on high fidelity audio radio sets through Bluetooth. There have also been increase in the use of smart phones in diverse areas of life such as in academics, industries etc., where the use of online lectures and video conference meetings have increased in recent times. It is evident that these technologies offer convenience and smart connectivity, on the downside however is the security concern resulting from these communications. Classical cryptography algorithms built into these consumer electronics are prone to quantum computing attacks, and with the steady growth of quantum computing and algorithms, it is only a matter of time before the current classical cryptography algorithms become obsolete. This aim of this paper is to design a light weight Ring Learning With Layered Errors Key Encapsulation Mechanism (RLWLEKEM), a CCA secure lattice based post quantum cryptography algorithm for consumer electronics (CSE) platform. Experiments were conducted on Raspberry Pi 5, which served as a representative testbed for resource constrained CSE devices. Results were gathered using the experimental test bed to compare the performance of RLWLEKEM with some selected cryptography protocols such as code based cryptography (CBC), and classical cryptography algorithms. Performance metrics used for comparison include encryption time, execution time, communication overhead and energy consumption. Experimental results show that RLWLEKEM outperforms the other compared cryptography protocols in terms of time to complete cryptography process, storage/communication overhead and energy consumption and thus was most suitable for deployment as post quantum cryptography key encapsulation mechanism on energy constrained CSE devices.
Abstract: The rise in technical features and capabilities of consumer electronics (CSE) devices ranging from smartphones, high fidelity (Hifi) radio systems, MP radio sets and IoT-enabled smart devices, have created new possibilities about their use and applications. You tube files can now be downloaded on smartphones and played directly on high fidelity aud...
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Research Article
Diagnostic Operating-mode Control of an Oil-immersed Power Transformer Based on Cumulative Damage
San'at Zafar Ugli Togaymurodov*
Issue:
Volume 14, Issue 5, October 2026
Pages:
239-244
Received:
28 September 2026
Accepted:
8 October 2026
Published:
31 October 2026
DOI:
10.11648/j.jeee.20261405.13
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Abstract: The relevance of the study is associated with the transition from separate recording of individual transformer diagnostic parameters to an integrated damage assessment followed by operating-mode control. The aim was to develop and experimentally verify a diagnostic control approach for an oil-immersed power transformer based on the combined effects of switching-induced mechanical loading, vibration fatigue, and thermal insulation ageing. The study was carried out on a 20 MVA, 110/6 kV oil-immersed transformer operating at a substation of a mining and metallurgical enterprise. Continuous monitoring of vibration acceleration, hottest-spot temperature, currents, and protection operation events was combined with cumulative-damage calculation, Fisher's adequacy criterion, and reliability indices. Diagnostic control reduced protection clearing time from 80 to 50 ms, annual switching-related damage from 8.75 to 4.862%, vibration-related damage from 4.0 to 1.6%, and thermal degradation from 3.28 to 0.30%. Total annual cumulative damage decreased from 16.0 to 6.8%, the equivalent failure rate from 0.16 to 0.068 year-1, while one-year reliability increased from 0.8521 to 0.9343. The results demonstrate that a physically interpretable combination of electrical, mechanical, and thermal degradation factors can provide a basis for real-time operating-mode control and improved transformer reliability.
Abstract: The relevance of the study is associated with the transition from separate recording of individual transformer diagnostic parameters to an integrated damage assessment followed by operating-mode control. The aim was to develop and experimentally verify a diagnostic control approach for an oil-immersed power transformer based on the combined effects...
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