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在压电半导体中,自由载流子的存在引起声阻尼,因此降低他们用作机电换能器的效率。由于载流子用超声速度漂移,当改变能量的转换过程时发现与声放大相联系的电声效应。分析了以一延迟棒加在表面上作负载而构成的半导体换能器转换能量的情况,描述能显示出漂移速度、电阻率、负载阻抗效应的换能器增益的计算结果[10 log_(10)(负载功率/有用功率)]。用很小的机械负载和载流子用超声速度漂移将能改善探测和发射的性能,在给主净电子增益的机械谐振附近,换能器的增益为正值。同时指出电声不稳定性发生的情况。
In piezoelectric semiconductors, the presence of free carriers causes acoustic damping, thus reducing their efficiency as electromechanical transducers. Since carriers drift with the ultrasonic velocity, the electroacoustic effect associated with acoustic amplification is found when changing the energy conversion process. The conversion energy of a semiconductor transducer consisting of a retardation rod added to the surface is analyzed, and the calculation of the gain of the transducer showing the effects of drift velocity, resistivity and load impedance [10 log_ (10) ) (Load power / useful power)]. Transducer gain is positive near the mechanical resonance of the main net electron gain, with small mechanical loads and carrier-ultrasonic velocities that will improve detection and emission performance. At the same time pointed out that the electro-acoustic instability occurs.