ML13155
LANSDALE Semiconductor, Inc.
In the S–parameters measurements, the IF is treated as a
two–port linear class A amplifier. The IF amplifier is meas-
ured with a single–ended input and output configuration in
which the Pins 16 and 7 are terminated in the series combina-
tion of a 47 resistor and a 10 nF capacitor to VCC ground
(see Figure 14. S–Parameter Test Circuit).
The S–parameters are in polar form a the magnitude (MAG)
and angle (ANG). Also listed in the tables are the calculated
values for the stability and factor (K) and the Maximum
Available Gain (MAG). These terms are related in the follow-
ing equations:
K = (1–IS11 I2–IS22I2 + I∆I2)/(2 I S12 S21 I)
where: I
∆
I = I S11 S22–S12 S21 I.
MAG = 10 log I S21 I/I S12 I + 10 log I K–(K2–1)1/2 I
where: K >1. The necessary and sufficient conditions for
unconditional stability are given as K>1:
B1 = 1 + I S11 I2 – I S22 I2 – I
∆
I2 > 0
Figure 14. S–Parameter Test Circuit
IF
Input
SMA
1.0n
1 IN1
C2
2 DEC1
3 VCC1
4 DETO1
5 DETO2
6 VCC2
7 LIMO1
47
1.0n
8 QUAD1
QUAD2 9
DEC2 15
VEE1 14
1.0n
RSSI 13
Buffer
RSSI 12
VEE2 11
SMA
LIMO2 10
1.0n
IF
Output
100n
10µ
+
VEE
IN2 16
C15
1.0n
47
Page 6 of 16
www.lansdale.com
Issue A
LANSDALE [ LANSDALE SEMICONDUCTOR INC. ]
