数字硅MOSFET微波特性的研究

Microwave Characteristics of Digital Silicon MOSFET

利用国内先进的 0 .6μm数字 Si-MOS工艺 ,设计了射频 MOSFET,并研究了其 DC和微波特性 :I-V曲线、S参数、噪声参数和输出功率。研究发现 ,数字电路用 Si MOSFET的频率响应较高 :频率为 1 GHz时功率增益可达 1 0 d B,2 GHz时为 8d B,4GHz时为 5 d B。 1 .8GHz时 ,1分贝压缩输出功率 1 2 .8d Bm,饱和输出功率可达 1 8d Bm,且最小噪声系数为 3 .5 d B。用提取的参数设计并研制了微波 Si MOSFET低噪声放大器 ,以验证MOS器件的微波性能。此放大器由两级级联而成 ,单电源供电 ,输入输出电容隔直。在频率 1 .7～ 2 .2 GHz的范围内 ,测得放大器增益 1 5± 0 .5 d B,噪声系数 N F<3 .8d B,1分贝压缩输出功率 1 2 d Bm;在频率 1 .5～ 2 .5 GHz的范围内 ,放大器增益大于 1 3 d B。

A RF MOSFET was designed and fabricated using an advanced 0.6 μm silicon MOS foundry of digital circuits, and its DC and microwave characteristics were studied:including DC I V curve, S parameters, noise parameter and output power. We found that the digital MOSFET's frequency response as follows: its power gain is 10 dB at 1 GHz, 8 dB at 2 GHz , 5 dB at 4 GHz. At 1.8 GHz It give 12.8 dBm of P 1dB output power, 18 dBm of saturation output power, and minimum noise figure of 3.5 dB. Using the parameters extracted, a microwave integrated low noise amplifier was developed and measured to verify the microwave performances of MOS device, which is cascaded by two stages with positively single power supplied, DC blocked by input and output MIM capacitors. The amplifier has a power gain of 15±0.5 dB, a maximum noise figure of 3.8 dB and 12 dBm of P 1dB output power from 1.7 GHz to 2.2 GHz, while from 1.5 GHz to 2.5 GHz, it gives a pwer gain of more than 13 dB.