You are thinking of big CPU clocks, this is not the speed of a single transistor switching, it is determined by whatever was accepted as the longest path of components for electricity to propagate through (think of a ripple adder as a simple example). You can have a much smaller separate clock and thus higher frequency for single purpose silicon when the path is significantly shorter.
60GHz here is talking about signal, you only need to create an oscillation at 60GHz not do fp multiply. There are various ways of doing so, but consider that it only takes three inverters to create a ring oscillator. As for the data - you don't need to fill the buffer at the speed which bits are sent, which is how you can interface with a lower frequency microcontroller, i.e the buffer is filled at a lower frequency but in large chunks i.e words.
Someone with proper EE and signal processing knowledge will explain more accurately but that's the crude idea (components frequency vs clock).
Not sure if this is what you are getting at but high speed comms modulate a signal up from a lower frequency to a much higher carrier frequency for transmission. Then the receiver modulates back down to baseband (the original frequency before modulation). This can be done with discrete hardware, no need to do the DSP with a CPU that can't reach those clock speeds. It's one of the reasons your 5GHz WiFi doesn't actually have a 2.5Gbps bitrate (satisfying the Nyquist criterion), but something closer to 1.3Gbps.
Source: graduate with MS EECE in Comms, Control, and Signal Processing in a couple months
> It's one of the reasons your 5GHz WiFi doesn't actually have a 2.5Gbps bitrate (satisfying the Nyquist criterion), but something closer to 1.3Gbps.
Ah, this is not what I meant but just as relevant. I think you are essentially saying that you don't have to send as many bits per second that the signal frequency is capable of? I suppose that would satisfy any arguments that focus on bit throughput.
At those kind of frequencies (and way higher), devices like oscillators, mixers and amplifiers (FETs) are typically fabricated on Gallium Nitride (GaN) or Gallium Arsenide (GaAs) substrates.
