This study conducts both experimental and statistical analyses of microinverter performance within a compact AC-PV module that integrates a PV panel and a microinverter without battery integration. Using measurement data in combination with correlation analysis, derived thermal indicators, and quadratic regression modeling, the research provides a comprehensive quantitative assessment of microinverter behavior under practical operating conditions. A central finding is that the PV module’s temperature rise above ambient, ΔT_module, serves as the most reliable single predictor of output power with a coefficient of determination of R² = 0.85. The coefficient determination of ΔT_module surpasses even solar irradiance and the microinverter temperature rise, ΔT_micro, with R² = 0.80 and R² = 0.75, respectively. This underscores the excess thermal loading of the module, rather than the absolute temperature alone. In contrast, ambient temperature (R² = 0.04) proves to be a negligible variable for output power prediction. Also, comparing experimental temperatures with semi-empirical models showed that the PV temperature formula captures key thermal behavior, and the difference between theoretical and measured values is around 12%. From a design standpoint, these results highlight that enhancing thermal management at the module–inverter interface can directly improve output stability and ensure battery integration in the long-term reliability of an AC-PV module in future studies.

This paper presents the design, fabrication, and measurement of a 3 GHz single-stage discrete bipolar junction transistor (BJT) low-noise amplifier (LNA) for S-band wireless communication applications. To minimize parasitic effects, simplify fabrication, and enable post-production tuning, the proposed design employs via-free open-stub microstrip matching networks and transmission-line biasing in place of conventional lumped components. Source and load terminations are selected from constant-gain and stability circles, synthesized through a double-stub approach, and validated using circuit/electromagnetic (EM) co-simulation in AWR and Sonnet. A prototype was implemented on a 60 mil RO4003C substrate and biased at VCE = 3 V, IC ≈ 15 mA. Measured performance includes 9.2 dB gain, a 1.5 dB noise figure (NF) at 3 GHz, and input VSWR < 2 across 2.7–3.3 GHz (≈20% fractional bandwidth). Two-tone testing with Δf ≈ 2 MHz confirms an IIP3 of −11 ± 5 dBm. The proposed work makes three key contributions: (i) it minimizes vias and lumped parts while maintaining wide bandwidth, (ii) it provides a practical workflow for termination selection based on stability and gain circles, and (iii) it demonstrates a low-cost, fabrication-friendly design with measured validation. These results confirm the LNA’s suitability for compact, wideband receiver front-ends in satellite communication, wireless backhaul, radar, and IoT systems.

This work describes the design and experimental testing of a low-noise amplifier (LNA) fabricated on a printed circuit board (PCB) and operating near 2 GHz. The amplifier uses a discrete bipolar junction transistor (BJT) together with fully distributed microstrip matching networks without relying on lumped matching components. The main design goal is to obtain stable operation with low noise figure and moderate gain over a wide frequency range while keeping the circuit tolerant to layout parasitics and fabrication variations. Circuit-level simulations are performed using AWR Microwave Office and are followed by full-wave electromagnetic simulations in Sonnet Software to account for layout-dependent effects. A prototype is fabricated on a 60-mil Rogers RO4003C substrate and characterized through S-parameter, noise-figure, and linearity measurements. Measured results show a gain of approximately 13.84 ± 1 dB over the 1.75–2.25 GHz frequency range, with a minimum noise figure of 1.615 dB at 2 GHz. Stable operation is maintained across the entire band, and the measured 1 dB gain compression point is approximately 0.5 dBm. The results demonstrate that a fully distributed microstrip matching approach provides a practical and reproducible PCB-based LNA solution for sub-6-GHz receiver front-end applications.