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In this paper, a novel Doherty Power Amplifier DPA based on a 10 W gallium-nitride high-electron-mobility transistor (GaN-HEMT) technology is designed using Advanced Design System (ADS) software. In the design, two different single Power Amplifiers (PAs) are combined using a Wilkinson power divider which is also used to connect the power to the load. The designed DPA operates in the range of 2.0-3.0 GHz and aims to achieve high efficiency, wide bandwidth and high output power for 5G applications. Simulation results showed a 40% fractional bandwidth and more than 44 dBm of saturated output power. In addition, the Power-Added Efficiency (PAE) and Drain-efficiency (Deff) are about 77% and 84%, respectively. A comparison with the other previous works shows enhancement in the maximum large-signal gain (L_S_Gain) in the average of 2.5 dB and an average PAE of about 10%. This improvement can be attributed to the deployment of the power divider/combiner proposed in the design and also the optimization of the components during the design.

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Accessing affordable and reliable energy services for cooking is important in most developing countries. Improving access to affordable energy reduces effects on human health and environmental influences caused by burning of various biomasses. This review examines the energy resources available in the world and their use in cooking. It also looks at challenges and the ways these energy resources are used as well as possible solutions to such challenges. The major challenges facing the use of available fuels are low efficiencies, high cost, un-sustainability and indoor house pollution that affect many people. The paper has identified that the use of combustion-less cooking, the use of solar for cooking, hydrogen and electrical systems that improve cooking activities and therefore overcome indoor and environmental pollution. Research findings indicate that the pressure-cooking concept improves energy efficiencies in boiling operations. Other energy efficiency improvement techniques in cooking are insulation, containment of escaping steam while cooking and automating the cooking vessel with micro-controllers. The overall efficiencies for electrical induction heating, natural gas, traditional cooking stoves, fuel wood stoves and electrical resistive heating was found to be 90%, 45-60%, 10%, 23-40% and 75% respectively. Induction cooking is both faster and more efficient than gas cooking, while electrical energy systems as a whole were found to be the cleanest, offering ease of control and versatility. The combination of a micro-controller automated insulated pressure cooker and induction cooker can highly improve the cooking efficiency. This is done by cutting a power supply using a relay controlling an induction cooker and therefore preventing the exit of steam. It is therefore identified that zero emission release during cooking will reduce both indoor and environmental pollution significantly.

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