|VSWR||VSWR is an initialism for “Voltage Standing Wave Ratio“. The bandwidth of an antenna is usually defined as the range of frequencies at which VSWR is less than 2.|
The voltage in a dipole is maximum at the ends, and 0 at the middle. The current is the opposite, with the maximum being in the middle, and being 0 at both ends. The following graph shows this:
You have to consider the placement of other components surrounding the PCB antenna. The following diagram shows the minimum recommended clearances between a PCB antenna and other components.
Note that shorting out an antenna is not an effective way of stopping it from communicating. At RF frequencies, a direct short with a piece of wire is no longer a direct short, and can for example, appear inductive. This means the antenna can still work, and sometime make it perform better! I have shorted out cellular modem antennas before with pliers and the signal strength increased!