Research On Tunable Maser Low Noise Amplifier

The maser is also called maser.It is a microwave amplifier developed by the principle of stimulated emission.For the maser technology,the early limitations were that it needed to be close to absolute zero and an externally enhanced magnetic field to work properly.With the continuous development of maser,various types of room-temperature semiconductor polariton maser(Room-temperature semiconductor polariton maser)have also been developed.Although there have been breakthroughs in achieving environmental and output power,if you want to use it at room temperature,It requires a huge footprint and expensive equipment,which greatly limits the practical application of Maser.As a frequent visitor to the receiver system,the amplifier plays an important role in the receiver front-end system.The performance of the low noise amplifier has a decisive influence on the noise figure,sensitivity and dynamic range of the entire transceiver system.For the entire transceiver system,the first-stage low-noise amplifier often has higher requirements on performance indicators.In military or some high-precision equipment,high-temperature superconducting receiver systems are now used to reduce system noise and increase sensitivity.But for the current high-temperature superconducting technology,the receiver front-end system,including filters and low-noise amplifiers,needs to work at a temperature of at least 77 K.The harsh conditions bring high prices,so basically it cannot be used in civilian facilities.This paper studies a tunable maser low-noise amplifier based on room temperature semiconductor maser technology.The low noise amplifier does not require an external DC bias.Instead,it is driven by the pump signal function and realizes the combination of frequency selection and low noise amplifier,which not only solves the power problem,but also has a huge optimization in space and cost.The research work of this article mainly includes the following aspects:1.A brief introduction to the development history of low noise amplifiers and HEMT transistors.2.The development of the maser is introduced in detail and the core theory of this article: the theory of the room temperature semiconductor maser is introduced.A brief introduction to the core ideas and verification methods of the theory.Based on this theory,215 MHz and 475 MHz fixed frequency maser low-noise amplifiers have been developed and designed.A noise of 3.3dB,a gain of 16.47 dB,a noise of 0.82 dB and a gain of 38.95 dB are achieved respectively.3.Modified on the basis of fixed frequency maser low-noise amplifier,designed two tunable maser low-noise amplifiers with power-up mode.The frequency modulation ranges are 250.2MHz-242 MHz and 261.4MHz-253.2MHz respectively.The lowest noise figure can reach 1.59 dB,the highest gain is 17.899 dB,and the 1dB compression point is about 20 dB in the passband.