DATA SHEET • SKY73001
20
19
18
17
NF (dB)
16
15
14
13
12
11
10
0
500
1000
1500
2000
2500
IF = 10 MHz
Frequency (MHz)
Figure 7. Noise Figure vs Frequency
Evaluation Board Description
The SKY73001 Evaluation Board is used to test the performance
of the SKY73001 direct conversion mixer. An Evaluation Board
schematic diagram is shown in Figure 8. The Evaluation Board
assembly diagram is shown in Figure 9.
Circuit Design Configurations
The following design considerations are general in nature and
must be followed regardless of final use or configuration.
1. Paths to ground should be made as short as possible.
2. The ground pad of the SKY73001 direct conversion mixer has
special electrical and thermal grounding requirements. This
pad is the main thermal conduit for heat dissipation. Since the
circuit board acts as the heat sink, it must shunt as much
heat as possible from the mixer. As such, design the
connection to the ground pad to dissipate the maximum
wattage produced to the circuit board. Multiple vias to the
grounding layer are required.
3. Two external output bypass capacitors are required on the
VCC pin. The values of these capacitors will change with
respect to the desired RF frequency. One capacitor should be
used for low frequency bypassing and the other capacitor for
high frequency bypassing. Special attention should be given
so that the smaller value capacitor does not go into self-
resonance at the desired RF frequency.
4. Wire wound balanced transformers (baluns) were used during
the test and characterization of the SKY73001. Ceramic
baluns can be used to create the differential input signals (i.e.,
RF and LO). However, their performance will limit the overall
system performance of the SKY73001.
Testing Procedure
Use the following procedure to set up the SKY73001 Evaluation
Board for testing. Refer to Figure 10 for guidance:
1. Connect a +3.0 VDC power supply using an insulated supply
cable. If available, enable the current limiting function of the
power supply to 100 mA.
2. Connect a signal generator to the RF signal input port. Set it to
the desired RF frequency at a power level of 0 dBm to the
Evaluation Board but do NOT enable the RF signal.
3. Connect a signal generator to the LOQ signal input port. Set to
the desired LO frequency at a power level of 0 dBm, but do
not enable.
4. Connect a spectrum analyzer to the IFQ signal output port and
terminate the IFI signal input port in 50
Ω.
5. Enable the power supply.
6. Enable the LO input signal.
7. Enable the RF signal.
8. Take measurements and repeat these steps for channel I.
CAUTION:
If any of the input signals exceed the rated maximum
values, the SKY73001 Evaluation Board can be
permanently damaged.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
101907D • Skyworks Proprietary and Confidential information • Products and Product Information are Subject to Change Without Notice • October 8, 2004
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