I'm looking for options to reduce harmonics in a small radio transmitter I've built.
I have tried a low-pass filter on the amplified output but it saps so much power that it's basically useless. I would try an active filter using an op-amp but I'm not sure if this could carry enough power through to the antenna coupling to be useful? I'm looking for 1 watt total power dissipation. A power MOSFET is the main switching element at the carrier frequency. I suspect this is the main problem as the square wave may introduce stronger harmonics than a sine wave? This is all a learning experience for me.
What other options might I try? This is a totally homebrew project so I'm not following a pre-designed schematic. Besides the harmonics, the transmitter works surprisingly well.
I have tried a low-pass filter on the amplified output but it saps so much power that it's basically useless. I would try an active filter using an op-amp but I'm not sure if this could carry enough power through to the antenna coupling to be useful? I'm looking for 1 watt total power dissipation. A power MOSFET is the main switching element at the carrier frequency. I suspect this is the main problem as the square wave may introduce stronger harmonics than a sine wave? This is all a learning experience for me.
What other options might I try? This is a totally homebrew project so I'm not following a pre-designed schematic. Besides the harmonics, the transmitter works surprisingly well.
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