I am doing a dummy load project for my Radio Frequency lecture and I am going to need help for this project.

I first started with 11 parallel resistors design, each resistor is 560 ohms and 1 watt. There is a must in this project and that is the signal strenght should not exceed -10 dBm so I need to place an attenuator to my design here.

If I can just do a normal attenuator with 50 ohm it will be fixed

To make it consistent over frequency, I need to make sure the PCB has a characteristic impedance of 50 ohm from the connector to the load, and that the resistors themselves are capable of being resistive up to my top frequency which is 1kHz. The resistors I used are surface mounted resistors and they can only handle 1W of power so there comes the problem, so I need to make a parallel or series connection with multiple resistors, this is a design challenge for me and I am open for your professional ideas to solve this dummy load and attenuator problem.

Thank you four time.