High Frequency Electronics and radio

Thread Starter

Robin Mitchell

Joined Oct 25, 2009
819
Hi all,

I have always wondered something...

I want to build a radio receiving circuit and wish to detect signals in the 100MHz region but this got me thinking. How can electronic circuits pick up signals greater than so many gigahertz? What frequencies can radio circuits really function at? What are the largest frequencies that electronic circuits can operate at? Can circuits really function at frequencies greater than 10GHz?

All the best,
Robin Mitchell
 

crutschow

Joined Mar 14, 2008
25,265
Microwave circuits are commonly used that operate above 100 GHz, with experimental circuits operating in the THz area. Of course at those frequencies you can't use wire to conduct the signals over any significant distance so some form of waveguide is typically used.
 

takao21203

Joined Apr 28, 2012
3,695
at 100 MHz a 3.5 Turns air coil has significant influence on the circuit.
At 300 MHz, a PCB trace can be used as inductor.

Generally, GHz circuits tend to be very small, and special structures are used on the PCBs, called microstrips.

Above 10 GHz isnt used in consumer electronics as far as I know.

100 MHz isnt difficult if you use Manhattan or "Dead bug" style on perfboard (with the copper side up).
But above that, it gets more and more difficult, with 800 MHz or so being the margin what you can do with conventional circuit technology.
 

ian field

Joined Oct 27, 2012
6,539
Microwave circuits are commonly used that operate above 100 GHz, with experimental circuits operating in the THz area. Of course at those frequencies you can't use wire to conduct the signals over any significant distance so some form of waveguide is typically used.
Just past millimetre wave radar is longwave IR.
 

alfacliff

Joined Dec 13, 2013
2,458
checkout J Chagdesh Bose ( I hope the spelling is right) he was working with milimeter waves back when marconi was working with long waves. He invented a lot of the stuff used today, waveguide, dielectric lenses, polarization shifting, p, and n type semiconductor detectors and a lot else.
 

ian field

Joined Oct 27, 2012
6,539
checkout J Chagdesh Bose ( I hope the spelling is right) he was working with milimeter waves back when marconi was working with long waves. He invented a lot of the stuff used today, waveguide, dielectric lenses, polarization shifting, p, and n type semiconductor detectors and a lot else.
In the earliest ventures into experimentation with Hertzian waves, no one had any notion of winding coils - the nearest anyone had to inductance was a hoop of metal.

It was basically UHF and up.
 

takao21203

Joined Apr 28, 2012
3,695
In the earliest ventures into experimentation with Hertzian waves, no one had any notion of winding coils - the nearest anyone had to inductance was a hoop of metal.

It was basically UHF and up.
Did you find this info on wikipedia? Can you cite any sources?
 
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