Invention Grant
US08456237B2 Low noise variable gain amplifier utilizing variable feedback techniques with constant input/output impedance
有权
利用具有恒定输入/输出阻抗的可变反馈技术的低噪声可变增益放大器
- Patent Title: Low noise variable gain amplifier utilizing variable feedback techniques with constant input/output impedance
- Patent Title (中): 利用具有恒定输入/输出阻抗的可变反馈技术的低噪声可变增益放大器
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Application No.: US13193604Application Date: 2011-07-29
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Publication No.: US08456237B2Publication Date: 2013-06-04
- Inventor: Feng-Jung Huang , Jean-Marc Mourant
- Applicant: Feng-Jung Huang , Jean-Marc Mourant
- Applicant Address: US CA San Jose
- Assignee: Integrated Device Technology, Inc.
- Current Assignee: Integrated Device Technology, Inc.
- Current Assignee Address: US CA San Jose
- Agent Tracy Parris
- Main IPC: H03G3/12
- IPC: H03G3/12

Abstract:
Variable feedback architecture and control techniques for variable gain amplifiers (VGAs) concurrently maintain, across a wide range of VGA gain settings, minimal input and output impedance variations, a low noise figure, low rates of change in noise figure, high signal-to-noise ratio (SNR), high quality of service (QoS), low distortion, high and relatively constant output third order intercept point (i.e., IP3 or TOI). Variable feedback counteracts impedance variations caused by gain variations. Compared to conventional high performance VGAs, noise figure is lower (e.g. 3 dB lower at maximum gain and 12 dB lower at minimum gain) and relatively constant, IP3 is higher and relatively constant, small signal third order intermodulation signal (IM3) tone slope is relatively constant and input and output impedances are relatively constant. As gain decreases, the noise figure advantage is nearly dB per dB compared to conventional high performance VGAs.
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