Transmit the PWM signals through RFIC?

[ayush742]

I need to transmit a PWM signal wirelessly at 5 GHz and receive it at the other end. Could you please suggest any COTS devices available and provide any recommendations?

 

[FvM]

I read "pwm" as general digital signal. But which frequency, minimal and maximal pulse width? Required pulse width resolution and accuracy?
What's the intended RF channel? Free space, wave guide or cable? Restrictions regarding RF level and modulation bandwidth, e.g. due to radio regulations?

 

[ayush742]

I am looking for this type of COTS module. Through which i can transmit the PWM signal.

• PWM Frequency: Likely in the kHz to MHz range, typical for IGBT gate driving.
• Minimal Pulse Width: Likely in the nanosecond (ns) range, given the 100 ns delay tolerance.
• Maximal Pulse Width: Likely up to microseconds (µs), based on typical gate control.
• Pulse Width Resolution: The system must have 100 ns resolution and high accuracy for real-time control.
• RF Channel: The primary RF channel is free space (5 GHz or 60 GHz wireless transmission).
• RF Level and Modulation Bandwidth: 9 GHz bandwidth (57–66 GHz), suitable for high-speed, low-power communication.

 

[danadakk]

Latency, transmit measured digital value and reconstruct using PWM on sink side ? Or
would that latency be objectionable ? Is PWM source a baseband signal ?


Regards, Dana.

 

[ayush742]

• This latency is not objectionable.
• Transmits the PWM signal directly using RF without digitizing and reconstructing it.
• Reconstruction on the sink side is unnecessary as the PWM signal itself is modulated and demodulated for direct use.
• Yes, the PWM signal is treated as a baseband signal and directly modulated onto the 5GHz or 60 GHz carrier for transmission.

 

[danadakk]

Maybe I am missing the point, why not simply gate the carrier ? Xmit side would
be simple. How much RF power is involved ?

Receive side you have issues like maintaining the deadband timing in gate drive,
as well as the latency due to carrier achieving a min S/N for reliability, detector
performance, fault handling.....all asking for time.....

Regards, Dana.

 

[mtwieg]

There are some COTs which do simple OOK modulation, but I've never seen one use a carrier frequency beyond 1GHz, and generally they are not for high data rates (maybe 100kbps).

Sending PWM signals for controlling power semiconductors via wireless is an extremely bad idea IMO. As in, I don't think it could possibly work robustly, regardless of carrier frequency, transmit power, etc.

A more reasonable approach would be to send data about duty cycle and period via wireless (with some error-checking), then use that to synthesize the pwm signal on the receiver end using a MCU. Hard to give specific recommendations without knowing more about to application.

 

[dick_freebird]

Seems overly elaborate to me and needy of data volume. Why not send duty factor as one word, use a DPWM off far end clock resource and update on change?