how to measure reverse power

i think you mean without meters... i advice with lamb..put a lamb arround the anttenna ...where the light is better swr is better :)

There are meters designed for this. They are put in the transmission line.

If your circuit does not allow this, such as the transmitter and antenna being on the same substrate material, it is more difficult. You might want to cut the substrate material and put a transmission line between them with the meter.

If your antenna is HF or VHF, get a Bird wattmeter. They are the best, but kind of expensive. There are also cheaper competitors. You also have to buy an "element" that plugs into the meter that is designed for your power level and frequency band. To measure the power in the reverse direction, just reverse the element. With forward and reverse power known, you can calculate SWR. You also have to specify what kind of coax connector you want. I bought one of the cheaper wattmeters about 5 years ago, works really well.

Hi star22

If you can connect Directional coupler. you can measure with low power
Instruments in one port the Tx power and the second port the reflected power (vswr=reflect/Tx). Don't forget to add the coupling.

PL