I am working on designing an antenna to detect 60Hz electric field. I came across the microstrip antenna being used to detect the field. Before designing the antenna I wanted to maek sure this is the right way, So I took a piece of 2 layer PCB(both the patch and ground plane were same size) of 10cmX15cm size and soldered a wire on one side and connected to a 2 Mohm resistor and measure voltage across the resistor through DAQ. I read approx. 1.7V when placed near a plugged heater. When unplugged I didn't read any. So I was positive that I am reading something on 60Hz. My question are as below.
1) Is this the right method? Am I reading 60Hz or some noise, static field, etc.?
2) I connected only one side of the PCB to resistor and measured voltage across the resistor. Do I need to necessarily ground the other plane(which is called ground plane)?
3) If I need to calculate the electric field(I have been researching on this from antenna-theory.com). By calculation, for 60Hz I would need a bigger size patch(like in kilometer range). Is this correct? If so, how come I am reading 60Hz in a small size?
4) I also looked on the other way considering the 2 sides as a plates of capacitor and FR4 material as a dielectric medium and measured the e-field. Is this the right method too? Considering that I have connected only one side of the plate and the other side is left open.