HSMS-286C-TR1 Avago Technologies US Inc., HSMS-286C-TR1 Datasheet - Page 9

• Manufacturer Part Number: HSMS-286C-TR1
• Description: DETECTOR DIODE,SOT-323
• Manufacturer: Avago Technologies US Inc.

Specifications of HSMS-286C-TR1

• Rohs Compliant: NO
• Diode Type: Schottky - 1 Pair Series Connection
• Voltage - Peak Reverse (max): 4V
• Capacitance @ Vr, F: 0.25pF @ 0V, 1MHz
• Package / Case: SC-70-3, SOT-323-3
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Max: -
• Power Dissipation (max): -
• Resistance @ If, F: -
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Two SMA connectors (E.F.
Johnson 142-0701-631 or equiva-
lent), a high-Q capacitor
(ATC 100A101MCA50 or equiva-
lent), miscellaneous hardware
and an HSMS-286B are added to
create the test circuit shown in
Figure 16.
The calculated input impedance
for this network is shown in
Figure 17.
Figure 17. Input Impedance,
3 µA Bias.
The corresponding input match is
shown in Figure 18. As was the
case with the lower frequency
design, bandwidth is more than
adequate for the intended RFID
application.
Figure 18. Input Return Loss,
3 µA Bias.
-10
-15
-20
-5
0
FREQUENCY (GHz): 2.3-2.6
2.3
FREQUENCY (GHz)
2.45
2.6
A word of caution to the designer
is in order. A glance at Figure 17
will reveal the fact that the circuit
does not provide the optimum
impedance to the diode at
2.45 GHz. The temptation will be
to adjust the circuit elements to
achieve an ideal single frequency
match, as illustrated in Figure 19.
Figure 19. Input Impedance. Modified
2.45 GHz Circuit.
This does indeed result in a very
good match at midband, as shown
in Figure 20.
Figure 20. Input Return Loss.
Modified 2.45 GHz Circuit.
-10
-15
-20
-5
0
FREQUENCY (GHz): 2.3-2.6
2.3
2.45 GHz
FREQUENCY (GHz)
2.45
2.6
However, bandwidth is narrower
and the designer runs the risk of a
shift in the midband frequency of
his circuit if there is any small
deviation in circuit board or diode
characteristics due to lot-to-lot
variation or change in temper-
ature. The matching technique
illustrated in Figure 17 is much
less sensitive to changes in diode
and circuit board processing.
5.8 GHz Detector Circuit
A possible design for a 5.8 GHz
detector is given in Figure 21.
INPUT
Figure 21. 5.8 GHz Matching Network
for the HSMS-286x Series at 3 µA
Bias.
As was the case at 2.45 GHz, the
circuit is entirely distributed
element, both low cost and
compact. Input impedance for this
network is given in Figure 22.
Figure 22. Input Impedance.
RF
9
FREQUENCY (GHz): 5.6-6.0
WIDTH = 0.045"
LENGTH = 0.073"
WIDTH = 0.016"
LENGTH = 0.037"
20 pF
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