Diode question - urgent help needed

[tOngEh]

Diode question

HI all, I met a problem in my simple circuit which i cant solve for the past 2weeks.
Attached in the circuit schematic and Output voltage. I wish to see the modulated carrier sitting the Squarewave with diode turn on/off effect. However, i cant justified the ringing output. Pls help. Thank you!

RF(1.5GHz sinwave carrier ) and DC(4MHz squarewave) are injected into a bias tee consisting a LC. Upon summing, the resultant signal is feed into a diode followed by a LC(passing the 1.5GHz carrier) to generate a ASK signal.

Thank you!

 

[keith1200rs]

Diode question

What is the diode?

I assume you have a current limiting resistor driving the DC?

The output capacitor looks like 180nF on your drawing - is that correct? If so, it will not have a good performance at 1.5GHz.

I assume you have a 50 ohm source and have terminated the load with 50 ohms?

You T piece looks nice, but I what is it? Is it a 50 ohm splitter? Is your 'scope set to 50 ohm input.

Building stuff on stripboard at 1.5GHz is a bit dodgy. You could use a bit of copper foil maybe.

Keith.