ABSTRACT
This chapter begins with the historical aspects and basic principles of the low-noise amplier (LNA) design, including basic topologies, minimum noise gure, and linearization techniques. When it is necessary to achieve high-gain and low-noise performance over a sufciently wide frequency range, the LNAs are designed using lossless matching circuits. However, the lossy feedback LNAs have been shown to be capable of the at gain over a very wide bandwidth with a sufciently low-noise gure, small size, and convenience in practical implementation. Several design techniques, including iterative optimization or interactive graphical design approach, are very useful in view of the many variables and conicting objectives of high gain, at and broadband gain, and low-noise gure. Finally, some practical circuit schematics of the broadband millimeter-wave LNAs are given and discussed.
