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STW81100

By using this topology the STW81100 is capable to deliver approximately 0dBm to a 50

Ω load with a return

loss grater than 10dB over the whole frequency band (3.3 to 4.4GHz).

Those results have been achieved on an FR4 substrate with a thickness of 350um.

For the differential to single ended conversion the 50 to 100

Ω - 3.3 to 4.4GHz - Johanson balun is recom-

mended (3700BL15B100).

9.2 Divided by 2 output

If the user's application does not require a balanced to unbalanced conversion, the output matching re-

duces to the simple circuit shown below (

Figure 26).

This solution can be easily used to provide one single ended output just terminating the other output at

50

Ω with a 3dB power loss.

Figure 26. Differential/single ended output network in the 1.65 - 2.2GHz range

A first solution to combine the differential outputs is the lumped LC type balun tuned in the 2GHz band

(

Figure 27). An output power of approximately 2 dBm is delivered to a 50

Ω load over the whole band

(1.65GHz to 2.2GHz).

Figure 27. LC lumped balun for the divided by 2 output

22nH

50 O hm

10pF

22nH

10pF

50 O hm

50 O hm

50 O hm

3nH

3nH

5.5nH

5.5nH

1pF

1pF

1nH

2.8pF

50 O hm

2nH