The length of coupler line (quarter wavelength) L
:Velocity factor
V0: Propagation velocity at vacuum
F0: Center frequency (Hz)
Example
Velocity factor 63％（＝0.63）, center frequency f0=1GHz
L= 47.25 (mm)
Required length becomes 47.25mm plus lead length.
[Applications]
* 3dB coupler
* 6dB, 10dB…..30dB directional coupler
* Power dividers/combiners
* Single balanced mixer
* Diplexer
* Power monitor
When you need a specific directional coupling other than our standard products like 18dB, 15dB coupler can be used for this purpose by setting the center frequency higher to make 18dB be target point on the 15dB coupling curves.
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