摘要
基于0.25μm PHEMT工艺,给出了两个高增益K波段低噪声放大器.放大器设计中采用了三级级联增加栅宽的电路结构,通过前级源极反馈电感的恰当选取获得较高的增益和较低的噪声;采用直流偏置上加阻容网络,用来消除低频增益和振荡;三级电路通过电阻共用一组正负电源,使用方便,且电路性能较好,输入输出驻波比小于2.0;功率增益达24dB;噪声系数小于3.5dB.两个放大器都有较高的动态范围和较小的面积,放大器1dB压缩点输出功率大于15dBm;芯片尺寸为1mm×2mm×0.1mm.该放大器可以应用在24GHz汽车雷达前端和26.5GHz本地多点通信系统中.
Two high gain K band MMIC LNAs（low noise amplifiers）on an advanced 0.25μm PHEMT process are reported. A structure with three cascaded circuits is used for increasing the gate width without limit. Source feed inductors appropriate for obtaining a good noise figure（NF） and high gain are adopted. A new resistor and capacitor network attached to the sources and drains is applied to suppress low frequency oscillations. For convenience, the same set of negative and positive voltage sources is provided through the resistance in the chip to the three-cascade circuit, which performs very well. The values of VSWin and VSWout of LNA2 are less than 2. The small signal gain from 24GHz to 26.5GHz reaches to 24dB and the noise figure（NF） is less than 3.5dB. Both LNAs have wide dynamic ranges and their chip areas are small,with dimensions of 1mm × 2mm × 0.1mm. The output power of the LNAs is greater than 15dBm at the ldB compressed point. These LNAs can be employed in front of a 24GHz radar and a 26.5GHz local distribution system（LMDS）.
基金
上海市科委基金资助项目(批准号:045115021)~~
