Fig. 2.9 N cascaded nonlinear stages, where a
1,1
...a
1,n
are the linear gains of stage 1...n and IIP
3,1
...IIP
3,n
denote the third order intercept points of stage 1 ... n, z
1
(t)
denotes the ouput signal of the first stage, and z
n
(t) denotes
the output signal of the n th stage . . . .................... 81
Fig. 2.10 Illustration of the 1-dB compression point . ............... 84
Fig. 2.11 Model used in noise figure calculations................... 87
Fig. 2.12 Cascade of k gain stages, each with noise . . ............... 88
Fig. 2.13 Receiver block diagram showing the G, NF, IIP
3
and SNR of the front end ............................. 90
Fig. 2.14 Four users are using their cellular phones at the same time,
where d is the maximum range from user to the base station
(dictated by standards; in our example this equals 400 m);
d
0
is the free space distance; d
2
is the minimum allowable
distance between user 1 and user 2, where user 2 uses
the next channel; and d
3
is the minimum allowable distance
between user 1 and user 3............................. 92
Fig. 2.15 The signal strength requirements of adjacent channels
in the DECT standard . . . ............................. 93
Fig. 2.16 Block diagram showing signal and interference level
at input and output of receiver front end . . . ............... 93
Fig. 2.17 Frequency spectrum at the output of the receiver
front end.......................................... 94
Fig. 2.18 Two equivalent representations of the front end:
(a) Interferers represented as narrowband noise.
(b) Interferers represented as tones . . .................... 95
Fig. 2.19 Signal strength at the output of the receiver front end . . ...... 98
Fig. 2.20 a) The heterodyne architecture b) The heterodyne
architecture with the corresponding input and output
impedance of the different subcomponents . .............. 100
Fig. 3.1a Generalized LNA topology........................... 108
Fig. 3.1b Lumped parameter representation of amplifier . . .......... 108
Fig. 3.2a LNA using lump ed parameter representation . . . .......... 112
Fig. 3.2b LNA with transformer matching at the input.............. 113
Fig. 3.3a Wideband LNA . . . ................................ 116
Fig. 3.3b The a circuit of core amplifier with loading .............. 117
Fig. 3.3c The f circuit of core amplifier with loading . .............. 118
Fig. 3.4a LNA using inductor at the gate for matching . . . .......... 128
Fig. 3.4b Small-signal equivalent circuit of LNA using inductor
at the gate for matching . ............................ 128
Fig. 3.5a LNA using source degrenerated inductor for matching . ..... 128
Fig. 3.5b Small-signal equivalent circuit of LNA using source
degeneratedinductorformatching......................... 129
Fig. 3.6a Alternative viewpoint of small-signal equivalent circui t ..... 130
xvi List of Figures