Re: Measuring Power at 76 GHz

Roger Ray


I use the Q8486A (33-50GHz) head with a waveguide taper, for measuring 76GHz. That reads high by approximately 7dB, when compared to a calibrated HP mixer. If you use a single diode mixer, the LO level can be high. So with the power head you are reading a total of LO and both sidebands, plus any other harmonics not cut off by the waveguide. The 40GHz head will be different, but not necessarily reading low.


--- In ukmicrowaves@..., "sm6afv" <jens.tunare@...> wrote:

I am building two new transverters for 76 GHz
based on DB6NT PCBs and DL2AM casings.
One with a separate CW TX optimized for maximum
output power.
For measuring power I am using a HP432A + R486A (40 GHz
Power Head).
I have no possibility to calibrate the R486A at 76 GHz.

After tuning of the 76 GHz TX I measure -5 dBm Output.
My question is what is the typical measuring error using
R486A Power Head at 76 GHz?
Does anyone in UK have experience with the use of R486A
Power Head?

/Jens - SM6AFV

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