Illustration of the Impedance Behaviour of Extremely Low-Profile Coupled Shorted-Patches Antennas for UHF RFID of People

Table 1

Simulated and measured electrical parameters of coupled-patch antennas.

Antenna	𝑆11,free (dB)	𝑆11,body (dB)	𝜂𝑡,free (%)	𝜂𝑡,body (%)	𝐺free (dBi)	𝐺body (dBi)
Dipole-excited simulation	−28	−15	54	57	1	1.1
Dipole-excited measurement	−13	−16	47	64	1.3	1.7
Directly excited simulation	−26	−18	56	58	1.1	0.9
Directly excited measurement	−23	−14	52	55	1.0	1.6