Faculty Publications
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Item Simulation of Radio over Fiber System for Microwave Signal Generation using Sub- Carrier Modulation Technique(Institute of Electrical and Electronics Engineers Inc., 2023) Singh, V.; Meena, K.S.R.; Singh, M.Nowadays, Radio over fiber (RoF) technology is used in a variety of applications, including wireless communication systems, satellite communication systems, and radar systems. In this paper, we reported a sub-carrier modulation with Amplitude Shift Keying (SCM-ASK) system which supports the transmission of various signals across a single-mode fibre with enhanced encryption efficiency. The quality of the received signal is usually poor in RoF systems, a number of factors may contribute to this problem, such as high bit error rates (BER), low Q-factor values, and the receiver may not be working in a high data rate network. To overcome this, the Q-factor needs to be raised while BER should be brought down to assured values. Using Opti-System software, SCM-ASK is investigated at various channel spacings and fibre lengths. Also, the RoF system performance is analyzed in terms of BER, Q-factor, and the eye diagram patterns. © 2023 IEEE.Item Microwave Photonics Based Millimeter-Wave Signal Generation Technique for 5G Systems(Institute of Electrical and Electronics Engineers Inc., 2024) Meena, K.S.R.; Singh, M.We report a novel millimeter-wave (mm-wave) signal generation scheme with microwave photonics (MWP) technology for advanced 5G optical links. This work combines two parallel Mach Zehnder modulators with a series Mach Zehnder modulator for better tunability and efficient bandwidth. The experiments confirm a 35-GHz mm-wave signal of highest power and a 60-GHz mm-wave of lowest power from a 15-GHz electrical drive input signal. The optical sideband suppression ratio (OSSR) and the radio frequency sideband suppression ratio (RFSSR) over a 0.5-km standard single-mode fiber link are 27 and 66 dBm, respectively. The harmonic suppression is also studied with modulation depth (m) and filter attenuation (a) parameters. The system s performance is evaluated in terms of eye patterns, quality factor ( Q), output power spectrum, and margin. In addition, the suggested photonic link plays a crucial role in developing 5G communication systems for generating high-frequency, ultrafast speed, and low-noise mm-wave signals © 1963-2012 IEEE.Item Widely-tunable optoelectronic oscillator using a microfiber coupler Sagnac loop(Springer, 2025) Meena, K.S.R.; Thayaba Nausheen, A.; Singh, M.An optoelectronic oscillator (OEO) integrating a Microfiber Coupler Sagnac loop and a parallel optical amplifier is proposed for the generation of wide-range, stable microwave signals. Unlike conventional OEOs that rely on dual-loop configurations, fixed optical delay lines, or bulky and lossy external filters, our design offers a solution capable of generating RF signals over a broad frequency range of 5–20 GHz. Sagnac loop provides high-resolution spectral filtering and substantial side-mode suppression, while the parallel optical amplifier enhances the loop gain and facilitates the stable oscillation across the entire tuning bandwidth. Our results confirm multi-tone microwave signal generation with a side-mode suppression ratio exceeding 50 dB. The single sideband phase noise of about ? 125 dBc/Hz at 10 kHz offset frequency is achieved for 10 GHz oscillation frequency. This hybrid architecture leads to highly stable, tunable, and pure microwave signal generation, making it suitable for radar systems, high-speed communication, and advanced sensing applications. © The Author(s), under exclusive licence to The Optical Society of India 2025.