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RF, Microwave, Ham Radio / Re: Passive RF SP12T Switch? Does it exist? Is there a better way?
« Last post by MartinL on Today at 12:09:37 pm »A 400Vpk-pk sine wave in a 50 ohm system corresponds to 400W of RF power throughput. That's quite a lot. Those Pasternack coax relays are only rated to 20W input power.
But at 5MHz you are in HF territory. You can look at amateur radio equipment for the HF bands for examples of how to do this. Generally, HF designs do not bother to try to maintain 50 ohm characteristic impedance through the relays. This is a reasonable choice because the relays are electrically extremely short (millimetres) compared to the wavelength (in this case 60 metres), so the effect of the short mismatched section is negligible.
At 400Vpk-pk, the RMS voltage is 141V, and RMS current into a 50 ohm load is 2.82A, so you can use common off the shelf relays rated for 250V AC at 3A or more.
But at 5MHz you are in HF territory. You can look at amateur radio equipment for the HF bands for examples of how to do this. Generally, HF designs do not bother to try to maintain 50 ohm characteristic impedance through the relays. This is a reasonable choice because the relays are electrically extremely short (millimetres) compared to the wavelength (in this case 60 metres), so the effect of the short mismatched section is negligible.
At 400Vpk-pk, the RMS voltage is 141V, and RMS current into a 50 ohm load is 2.82A, so you can use common off the shelf relays rated for 250V AC at 3A or more.
