Beam pattern of STA IR0507E Middle-Range RFID Reader
I would like to know the beam pattern formed by the STA IR0507E Middle-Range RFID Reader if anyone knows. I have been trying to figure out if the signal is transmitted in a linear fashion or circular pattern. I have placed my reader in a closed rectangular cabinet which is 6 feet high and 2.5 feet wide. The reader is facing downwards and is attached to the ceiling in the cabinet right in the centre. I have used RF 3-axis field strength meter to figure out the beam pattern however even after taking hundreds of readings I am not able to figure out the beam pattern.
Specification -
Air Interface protocol : ISO 18000-6C (EPC Class 1 Gen 2) ISO18000-6B Frequency Band 902MHz - 928MHz, 865MHz - 867MHz, and sub-bands Channels 50 (applicable to 902.5-927.5MHz frequency range) Channel spacing 500KHz (applicable to 902.5-927.5MHz frequency range) RF Power 0 to +31dBm Receive Sensitivity -80dBm Antennas Single unit with inbuilt antenna
Pictures of the reader
Within a metal box you will have reflections of the RF signal from the antenna, possibly also standing waves. These will superimpose with the RF signal from the antenna and create a RF pattern which likely differs from what you are expecting.
If you want to measure the beam pattern of your antenna, you can either do the measurement in open space (with no metal withiin your measurement area. Or you measure in an anechoic chamber, which is designed for that very frequency range.