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无电感的泛音晶体振荡器实践证明,对于晶体振荡器,如果把石英晶体激励在其机械谐波上(如三次谐波或五次谐波),则其频率稳定度会比激励在基波上时高。但是这样作通常要有一个对该谐波频率谐振的LC选频回路。这里介绍的是把石英晶体激励在机械谐波上的晶体振荡器(图1)却没有电感L,而是利用晶体管T_1、T_2组成的二端网络伏—安特性的负阻区,在此区域内二端网络的阻抗呈感性。场效应管T_3是稳流器,借以降低电源电压变化对振荡频率的影响。实验表明,对于1兆赫(Q=2×10~5,R_1=9.1千欧,R_2=1.3千欧,R_3=15千欧,C_1=390微微法,
Inductance-free overtone crystal oscillator Practice has shown that for crystal oscillators, if the quartz crystal excitation in its mechanical harmonics (such as the third harmonic or fifth harmonic), the frequency stability than the excitation in the fundamental High However, this usually requires an LC tank circuit that resonates at this harmonic frequency. Here is the quartz crystal excitation in the mechanical harmonic wave crystal oscillator (Figure 1) has no inductance L, but the use of transistors T_1, T_2 consisting of two-terminal network volt-ampere negative resistance region, in this region The impedance of the two ends of the network is sensual. FET T_3 is a current regulator, in order to reduce the power supply voltage changes on the oscillation frequency. Experiments show that for 1 MHz (Q = 2 × 10 -5, R_1 = 9.1 kΩ, R_2 = 1.3 kΩ, R_3 = 15 kΩ, C_1 = 390 pico-