Hi,
I am designing a 50 ohm 10 watts dummy load for 100-1000MHz frequency range. The signal strength should not exceed -10dBm. The load must be able to dissipate 5 watts minimum, that is +37dBm. The output to the test equipment must be no more than -10dBm. So I need an attenuation of 47dB but to make it easy lets say 50dB.
After the load as you can see in the schematic picture there is 3 different attenuators. The first one is 20dB attenuator for 5W dissipation, second one is 20dB-50mW dissipation and the last one is 10dB-50mW dissipation. You can see the values of the resistors on the schematic picture.
Specification for the PCB board:
Trace thickness : 0.036mm
Substrate height : 0.8mm
Trace Width : 1.5mm for 50ohms
Substrate Dielectric : 4.3
One thing that I couldn't figure out here is the width of the tracks when routing the attenuators as you can see some of them routed with a narrow line. Should it be as thick as 50ohms or something different considering the values, I don't know this because I have never seen it before. Long story short I need help with the circuit and routing the microstrip to have a good impedance match.
I have a problem with appliying this to a PCB board I know I should arrange R3-R6 symmetrically around the input connector, keeping the current path loops as short as physically possible. But I couldn't figure out myself. If you guys can guide me with placing the resistors and routing my problem will be solved.
I did something on my own you can check it below but I am pretty sure that is not the best way to do it. So waiting for your help.
Thank you for your time.
I am designing a 50 ohm 10 watts dummy load for 100-1000MHz frequency range. The signal strength should not exceed -10dBm. The load must be able to dissipate 5 watts minimum, that is +37dBm. The output to the test equipment must be no more than -10dBm. So I need an attenuation of 47dB but to make it easy lets say 50dB.
After the load as you can see in the schematic picture there is 3 different attenuators. The first one is 20dB attenuator for 5W dissipation, second one is 20dB-50mW dissipation and the last one is 10dB-50mW dissipation. You can see the values of the resistors on the schematic picture.
Specification for the PCB board:
Trace thickness : 0.036mm
Substrate height : 0.8mm
Trace Width : 1.5mm for 50ohms
Substrate Dielectric : 4.3
One thing that I couldn't figure out here is the width of the tracks when routing the attenuators as you can see some of them routed with a narrow line. Should it be as thick as 50ohms or something different considering the values, I don't know this because I have never seen it before. Long story short I need help with the circuit and routing the microstrip to have a good impedance match.
I have a problem with appliying this to a PCB board I know I should arrange R3-R6 symmetrically around the input connector, keeping the current path loops as short as physically possible. But I couldn't figure out myself. If you guys can guide me with placing the resistors and routing my problem will be solved.
I did something on my own you can check it below but I am pretty sure that is not the best way to do it. So waiting for your help.
Thank you for your time.
