I want to use a passive device to apply a 1V and 1MHz signal in a transmission line, While I am sweeping the frequency from 300kHz to 6GHz by Vector Network Analyzer (VNA) in that transmission line too.
I am new in RF field, and I tried the bias tee built in the VNA. But it filters the signal from the signal generator, and only it can pass 1v and 50kHz signals to the transmission line.
I am wondering which one of Diplexer or resistive power dividers is suitable for this job.
Have you noticed that 300 kHz is less than 1 MHz? If you are sure that you want a bottom measurement frequency to be 300 kHz, then that rules out a diplexer, leaving you only with a wideband device like a resistive power divider.
An alternative is to split the measurement into two bands, say DC-F resistive, and F to 6 GHz diplexing, where F is some convenient intermediate frequency like 10 MHz or 100 MHz that makes both devices easier to buy or build.
Using a resistive power divider will of course put a series resistance in the way of your DC bias. This may or may not matter depending on whether you need to supply much current.
