Design And Application Of Four Source Semiconductor Microwave Oven Control System

Since the birth of the microwave oven in the 1940 s,it has gradually entered many families.Traditional microwave ovens use a magnetron to generate microwaves,and a magnetron is essentially a diode placed in a constant magnetic field.The electrons emitted by the cathode in the magnetron interact with the high-frequency electromagnetic field under the influence of a constant electric field and a constant magnetic field perpendicular to each other,and convert the DC electric energy obtained from the constant electric field into microwave energy,thereby achieving the purpose of generating microwave energy.The microwave energy generated by the traditional microwave oven is in a frequency band between 2.4GHz and 2.5GHz in frequency spectrum,the frequency and phase are not adjustable,and the power is undetectable,that is,the microwave output is an open-loop control state.The semiconductor microwave oven uses digital chip to generate a low-power microwave signal,which is amplified by a power amplifier LDMOS to obtain microwave energy capable of microwave heating.Because the microwave signal of the semiconductor microwave oven is generated by the digital chip,the microwave frequency,phase and amplitude are adjustable;At the same time,by designing the power amplifier circuit,the forward power and reverse power of the semiconductor microwave oven can be detected,and then according to the detection,the power information is closed-loop controlled by the semiconductor microwave heating system.This system uses the lightweight FreeRTOS system and is developed based on C++ language technology.At the same time,the system has the following functions: key input;digital display;frequency,phase,power adjustment of microwave signal;power closed-loop control;multi-source matrix control.In terms of software design,according to the logical relationship and timing requirements of each part,the program is reasonably planned,and the resources of the MCU are effectively utilized to ensure the reliable operation of the program.The sampling data of analog signal is subjected to software filtering to eliminate the abnormal data of the interference and ensure the stable operation of the system.According to the software and hardware design of the four-source semiconductor microwave oven,the closed-loop control of the four-source semiconductor microwave oven is finally realized: the forward power and reverse power of the power amplifier are detected by detection module,and the detected data is transmitted to the main control module,the main control module adjusts the signal source module according to the feedback.After completing the software and hardware design and debugging of the system,the four-source semiconductor microwave oven can perform stable power output operation according to the parameter setting of the key input.Meanwhile,the frequency,phase and amplitude of the output microwave signal can also be adjusted according to the set parameters.Finally,the function of the four-source semiconductor microwave oven prototype was tested.By using power meter,spectrum analyzer and high-frequency oscilloscope and other equipment,the frequency modulation,phase modulation,amplitude modulation and other parameters of the prototype are tested separately,and the test results are also in line with the previous design parameters.