Low noise variable gain amplifier utilizing variable feedback techniques with constant input/output impedance
AssigneeIntergrated Device Technology, Inc.
InventorsFeng-Jung Huang, Jean-Marc Mourant
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AssigneeIntergrated Device Technology, Inc.
InventorsFeng-Jung Huang, Jean-Marc Mourant
Estimating the term…
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.
A device comprising a variable gain amplifier (VGA) having at least one variable feedback, wherein the at least one variable feedback comprises first and second components provided with coordinated control that, during operation of the VGA, results in concurrently providing a common adjustment to a first function of the VGA and a complementary adjustment to a second function of the VGA.
A device comprising a variable gain amplifier (VGA) having first and second variable feedbacks configured to concurrently provide, during operation of the VGA, a common adjustment to a gain control function of the VGA and a complementary adjustment to an impedance control function of the VGA.
A device comprising a controller configured to control first and second variable feedbacks in a variable gain amplifier (VGA) to concurrently provide, during operation of the VGA, a common adjustment to a gain control function of the VGA and a complementary adjustment to an impedance control function of the VGA.
Dependencies are inferred from the claim text.