lt5560 Linear Technology Corporation, lt5560 Datasheet - Page 20

• Manufacturer Part Number: lt5560
• Description: 0.01mhz To 4ghz Low Power Active Mixer
• Manufacturer: Linear Technology Corporation

APPLICATIO S I FOR ATIO
LT5560
Table 6. Output Port Differential Impedance (Parallel Equivalent)
In cases where the calculated value of C2 is less than the
internal output capacitance, capacitor C10 can be used to
improve the impedance match.
20
FREQUENCY
(MHz)
1500
1900
2150
2450
3600
140
240
360
450
750
900
70
1098 || –j3185
1082 || –j1600
1082 || –j974
1093 || –j646
1083 || –j522
1037 || –j320
612 || –j95.7
188 || –j53.1
IMPEDANCE
946 || –j269
655 || –j162
592 || –j122
662 || –j108
OUTPUT
(Ω)
U
REFLECTION COEFFICIENT (Z
U
0.913
0.912
0.912
0.913
0.913
0.910
0.903
0.870
0.865
0.883
0.879
0.756
MAG
W
Figure 11. Output Return Loss vs Frequency
for Different Matching Values
–10
–15
–20
–25
–30
–5
0
ANGLE (DEG.)
0
3
–11.0
–17.8
–21.1
–34.5
–44.6
–50.0
–55.4
–88.7
U
–1.8
–3.6
–5.9
–8.9
4
O
500
= 50Ω)
6
FREQUENCY (MHz)
7
1000
Table 7 lists actual component values used on the
LT5560 evaluation boards for impedance matching at
several frequencies. The measured output return loss
vs frequency performance is plotted for several of the
cases in Figure 11.
Table 7. Component Values for Output Matching
Note 1: A better 70MHz match can be realized by adding a shunt 180nH
inductor at the C10 location.
1500
CASE
1
2
3
4
5
6
7
8
8
2000
FREQ.
(MHz)
1900
140
240
380
450
900
10
70
5560 F11
2500
WBC16-1TL 16:1
WBC16-1TL 16:1
HHM1515B2 4:1
MABAES0061
MABAES0061
MABAES0061
MABAES0061
HHM1525 1:1
4:1
4:1
4:1
4:1
T2
(pF)
1.5
0.5
C2
-
-
-
-
-
-
L3, L4
(nH)
220
120
3.9
68
68
27
0
0
(pF)
C10
1.5
2.2
-
1
-
-
-
-
1
(@12dB RL)
1820-2000
110-170
175-300
290-490
360-540
850-940
MATCH
3-60
3-60
BW
5560f