标题: Basic Concepts in RF Design__ [打印本页] 作者: RGB_lamp 时间: 2022-8-17 11:09 标题: Basic Concepts in RF Design__ Basic Concepts in RF Design, y* M- R- C) l" L$ R
Overview. `" G* g' |$ q
System Theory 9 C/ M( q6 W2 J5 N6 L1 _; CEffects of Nonlinearities8 o- x4 |8 z+ a/ Q9 u7 A
Gain Compression; c9 Y4 i; Z! w: ^
Desensitization and Blocking ! Q- }& H- R6 k) Z3 {3 m# ^CroSSModulation* [2 J0 K/ v& o0 G7 b/ D# r* v
Intermodulation: k4 ~ B8 _! {. n
Adjacent Channel Power Rejection 4 c5 S6 A. e# Y9 O& sRandom Signals - p% S8 `/ v/ WNoise and Noise Figure ' l0 S8 M% q( D2 s: z# PInput Referred Noise& V5 s9 O% X3 Q$ z
Noise Figure of Lossy 9 V, p; y0 q7 X( ~8 e8 F) p+ H' a
) Q3 ]. A) H6 ]2 H! |1 oSystem Theory (1) + a# f8 h8 T/ _4 i/ ^Linear Systems : h( [3 Z) S+ J- {4 y1 1 x ® y 2 2 x ® y" g( F0 s( @+ a- @/ j
1 2 1 2 ax + bx ®ay + by- v$ I2 p) k2 ~: m* j1 w( J
If inputs x1 and x2 generate outputs y1, y2! W7 I9 ^# ^2 @6 b7 M
For a linear system output can be expressed as a linear combination of inputs7 N9 }; {+ z9 n6 Y& p8 m' V# A
for all values of the constants a and b 0 j6 D# m7 `" r2 J# L2 ?5 aTime Invariant Systems; Q% B% [$ r, U5 D6 v O: l
For a time invariant system time shift in input results in the same time shift in output, J) I, Q" }) E# b
x(t )® y(t ) then x(t -t )® y(t -t )+ n# z2 H+ W& y4 a/ `2 I: H
Any system that does not satisfy this condition is nonlinear 6 M6 R+ S( q1 ?0 U3 V. R. \# aObs. A system is nonlinear if it has nonzero initial conditions ' u# F* Y( Y: f6 U: f ^, w8 Xfor all values of t! y! v2 ^6 [5 d2 n" Q- V
