Page 362 - Complete Wireless Design

Support Circuit Design

Support Circuit Design 361

Figure 8.31 (a) Balanced input; (b) Unbalanced input.

Figure 8.32 Narrowband balun structure.

8.5.2 Balun design
Presented are two designs—one lumped balun for VHF and under, and anoth-
er for microwave and above as a distributed circuit.

Narrowband lumped balun (Fig. 8.32)
R R
B
U
1. L .
1 f
6.28
2. L L .
2 1
1
3. C .
1
(6.28 f) ( R R )
U B
4. C C .
2 1
where R unbalanced source or load resistance, ohms
U
R balanced source or load resistance, ohms
B
f center frequency, Hz.
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