I am using the ADL5801 as a UHF->IF converter. The chip's datasheet shows on fig.21 page 11 the RF port return loss. The first half of UHF band is poor since it begins at -5 down to -10 dB. There are no information concerning the S11 matching in the UHF band in the datasheet.
How can i improve the S11 of the RF port in UHF band ?
Thanks in advance to those who can help
The ADL5801 can provide a good match all the way down to DC at the RF input port. The RF port return loss shown in fig.21 on page 11 is a limitation from the offchip balun and DC blocking capacitors used. For lower frequencies you can use the input devices shown in the attached document.