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Diodes dc bias on rat race mixer

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klp

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Hello, I would like to design a rat race mixer. do I need to dc bias the diodes?
and what is the topology of the bias circuits of two diodes?
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vfone

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Generally, diode mixers don't need DC bias (as diode detectors needs) because the diodes works as switches, where the switching signal is given by the LO.
 
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klp

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Generally, diode mixers don't need DC bias (as diode detectors needs) because the diodes works as switches, where the switching signal is given by the LO.

Thank you for you answer, so how I can be sure the diodes will be in their non-linear region?
 

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The diodes are opened (you can say biased) by the relative strong LO signal. The diodes works as switches, and to get the best linearity of the mixer, the transient state between ON and OFF should be very short. This is done increasing the level of the LO up to a maximum safe level.
 

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