Dielectric Resonator Antenna E field absolute open cavity 1.8 GHz

Video animation of the absolute value of the electric field at 1.8 GHz of a cylindrical DRA placed within an open metallic cavity.

Videos

 

RF diode power detector circuit construction

RF Diode Power Detector Experiment with mobile phone

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RF Diode Power Detector Experiment with Mobile Phone

(Firstly, sorry for the 'noisy' sound for the duration of this video. I tried to put the mobile phone as far as possible from the camera to reduce this terrible interference whilst still allowing my hands to reach the circuit and execute the measurements).

Amendment: During the video presentation, I've incorrectly mentioned that diode BAT42 has a Vf=0.45V, while BAT41 has Vf=0.25V. These Vf values are not correct. I checked that for BAT42, Vf=0.65V and for BAT41, Vf=0.45V. Anyway, the point is that the lower the Vf of the diodes used for this circuit the brigher the LED can become.

The experiment investigates the behaviour of a RF power detector when placed next to a transmitting mobile phone, in three different ways:
1) Optical emission through LED
2) Investigation of signal output of circuit using an oscilloscope
3) Listening to the output of the RF detector using a small audio amplifier (this step wasn't necessary I think, as the 'sound' of the detector was audible as an interference during the video captured by the camera..)

The results are compared against the GSM time slot format (to see in detail the GSM standard I am referring to during the video, check this link: http://www.rfcafe.com/references/electrical/gsm-specs.htm ).

 

RF diode power detector circuit schematic

RF diode power detector circuit construction RF diode power detector circuit construction
(left) Top view and (right) bottom view of the constructed circuit