Q.
How does ADL5801 active mixer perform when driven single-ended on both its RF and LO ports without baluns? In some applications, baluns/transformers are not preferred, due to certain requirements such as cost.
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A.
It is possible to drive the RF and/or LO ports of active balanced mixer, such as the ADL5801, without balun(s) for single-ended operation. To do this, one input is ac-coupled to ground and the signal (LO or RF) is ac-coupled into the other input. In the example shown, the unused input was ac-coupled to ground using 100pF capacitor.
As can be seen from the plot below, the mixer maintains excellent IP3 over a broad frequency range. The downside of this mode of operation is approximately 3 dB of conversion loss compared to a conversion gain of +1.5dB when the RF input is driven differentially..
The dual channel mixer, ADL5802, can also be operated in this mode.
