I am building up a radio harvesting circuit on WIFI signal, but I fail. Actually I am very new to antenna and RF aspects.I have several questions about the circuit.
First of all, I follow this schematic diagram from this article - http://www.hindawi.com/journals/apec/2010/591640/
Equipment that I have used: 6X 1N5819 DO-41 1A/40V diodes 17X 1pf ceramic capacitors 5X 0.1uH 0307 Axial-Lead Inductor 1X 2DBI 2.4-2.5GHz wifi pcb internal ipex antenna , like this:[IMG] 1X UNI-T UT33C DMM [IMG]
C1 is made up of 11X 1pf capacitor in series. L1 is made up of 5x 0.1uH inductor in parallel. C2=C3=C4=C5=C6=C7=1pf capacitor
The result I have encountered:
When I place the antenna vary the distance between 1cm to 3meters in any direction from my home wifi router, zero volt across Test point 3 with ground point , even zero volt test point 1,2 with ground point measured by the DMM.
I doubt at some area that I may misunderstand:
- What is MS in the schematic diagram that illustrated in the research ?
- Do I use wrong type of capacitor or diode or inductors? Since I have found some capacitors, inductors and diodes that specifically used in RF.
Do I need earth the antenna ? Actually, the ground point of antenna I have connected to the earth poin that near to C7 which is also connected to DMM negative(COM) pin. And I just follow this IPEX instruction: [IMG]
Is the antenna too weak ? Since I have only 2DBI gain of antenna, however, I wonder why I even can not get 0.1mV when I place the antenna very very close to the home wifi router.
Apart from this, a very strange phenomenon occur in this circuit: When I change the diodes to 1N4004 and keep other equipment unchanged, and placing the antenna near to a charging mobile phone or wifi router (on top of the device), there is a reading, like 30-50 mV shown in DMM. I wonder is this reading due to the AC charging current?
I hope someone can help me. Thanks all
(Since I dont know how to place the diagram to the post here. So I may provide the post on other forum for reference, Please forgive me to do this. Sorry. http://www.electronicspoint.com/threads/problem-on-radio-energy-harvesting-circuit-is-cockcroft-walton-circuit-fail.275060/ ==> picture inserted by Wouter)