I have designed an RF power amplifier that operates close to 100 MHz and amplifies signals from 50mW to about 2W. Everytime I switch it on, the voltage on my lab power supply drops even though the current is within limits. It also makes a weird buzzing noise. I realised that the RF signal is finding its way into the power supply(2V peak-peak) inspite of the 1uH choke coil L2 and the decoupling capacitors C7 and C8. Is that why the power amplifier is behaving weirdly. If so how do I solve the problem? Also the problem only occurs if I connect the antenna. I am not sure why that is so too. Could it be because of some kind of impedance mismatch or EMI?