An Electrically Small On-Chip Antenna Scaled down to One-Twentyfifth by One-Fiftieth of Wavelength

An electrically small on-chip antenna for RFID tags operating at 5.8 GHz is presented. The proposed antenna has dimensions of 2.1 mm (λ/25) by 1.2 mm (λ/50), implemented in a 0.18 μm pure CMOS technology. The antenna consists of two loops. By changing the size of the inner loop, we can manage the antenna impedance while maintaining its gain. The antenna has a gain and a bandwidth of -22.21 dBi and 4.9 GHz, respectively.