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Intrinsic stability of the heterojunction bipolar transistor(HBT) was analyzed and discussed based on a small signal equivalent circuit model.The stability factor of the HBT device was derived based on a compact T-type small signal equivalent circuit model of the HBT.The effect of the mainly small signal model parameters of the HBT on the stability of the HBT was thoroughly examined.The discipline of parameter optimum to improve the intrinsic stability of the HBT was achieved.The theoretic analysis resul... 相似文献
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采用碳膜覆盖于SiC晶片表面,作为SiC离子注入后高温激活退火的保护层,1650℃20 min高温退火后,有碳膜保护的SiC晶片表面粗糙度RMS只有0.6 nm,无明显形貌退化。AZ5214光刻胶在不同温度条件Ar气氛围下碳化40 min,光刻胶均转变为纳米晶体石墨化碳膜。进行Raman测试表明,碳膜D峰和G峰的比值随碳化温度升高而增大,800℃高温碳化形成的碳膜ID:IG达到3.57,对高温激活退火SiC表面保护效果最佳,经过Ar气氛围下1 650℃20 min激活退火后,有碳膜保护和无碳膜保护的SiC表面粗糙度RMS分别为0.6 nm和3.6 nm。 相似文献
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制作了发射极面积为1μm×15μm×4指的InP DHBT器件,器件拓扑使用了共基极和共发射极两种结构,通过负载牵引测试系统对器件功率特性进行测试。在功率优化匹配条件下,所测得最大输出功率密度和相应的功率附加效率(PAE)在10GHz下为1.24W/mm和50%,在18GHz下的数据为0.82W/mm和26%。测试同时表明,共发射极结构相对稳定和易于匹配,共基极模式具有更大的输出功率潜力,但需要进一步解决难于匹配、容易振荡和寄生参量影响等问题。在功放电路设计中,可以根据不同需求选择合适的电路拓扑结构。 相似文献
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A virtual loop model was built by the transmission analysis with virtual ground method to assist the negative-resistance oscillator design, providing more perspectives on output power and phase-noise optimization. In this work, the virtual loop described the original circuit successfully and the optimizations were effective. A 10 GHz high-efficiency low phase-noise oscillator utilizing an InGaP/GaAs HBT was achieved. The 10.028 GHz oscillator delivered an output power of over 15 dBm with a phase-noise of lower than -107 dBc/Hz at 100 kHz offset. The efficiency of DC to RF transformation was 35 %. The results led to a good oscillator figure of merit of-188 dBc/Hz. The measurement results agreed well with those of the simulations. 相似文献
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A 6 GHz voltage controlled oscillator (VCO) optimized for power and noise performance was designed and characterized. This VCO was designed with the negative-resistance (Neg-R) method, utilizing an InGaP/GaAs hetero-junction bipolar transistor in the negative-resistance block. A proper output matching network and a high Q stripe line resonator were used to enhance output power and depress phase noise. Measured central frequency of the VCO was 6.008 GHz. The tuning range was more than 200 MHz. At the central frequency, an output power of 9.8 dBm and phase noise of -122.33 dBc/Hz at 1 MHz offset were achieved, the calculated RF to DC efficiency was about 14%, and the figure of merit was -179.2 dBc/Hz. 相似文献
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A 6 GHz voltage controlled oscillator (VCO) optimized for power and noise performance was designed and characterized. This VCO was designed with the negative-resistance (Neg-R) method, utilizing an InGaP/GaAs hetero-junction bipolar transistor in the negative-resistance block. A proper output matching network and a high Q stripe line resonator were used to enhance output power and depress phase noise. Measured central frequency of the VCO was 6.008 GHz. The tuning range was more than 200 MHz. At the central frequency, an output power of 9.8 dBm and phase noise of-122.33 dBc/Hz at 1 MHz offset were achieved, the calculated RF to DC efficiency was about 14%, and the figure of merit was -179.2 dBc/Hz. 相似文献
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具有在片稳定网络的GaAs HBT微波功率管 总被引:1,自引:0,他引:1
采用GaAs标准MMIC工艺制作了具有片上RC并联稳定网络的InGaP/GaAs HBT微波功率管单胞.依据K稳定因子,RC网络使功率管在较宽的频带内具有绝对稳定特性.Load-pull测试表明RC网络没有严重影响功率管的大信号特性,在5.4GHz饱和输出功率为30dBm,在11GHz 1dB压缩点输出功率大于21.6dBm.功率合成电路验证了该功率管具有高稳定性,非常适合制作微波大功率HBT放大器. 相似文献