Design of compact 2.45 GHz microstrip antenna

Based on shorting pin technique and common PCB (printed circuit board) technology, a 10 mm-diameter microstrip antenna is designed and manufactured to meet critical miniaturization requirement for special applications. The antenna is fabricated on microwave substrate (tandelta = 0.001, epsir=3.5,h = 4 mm). It resonates at 2.45 GHz (ISM band); while the impedance bandwidth reaches 104 MHz and the gain approach 0 dBi. Both theoretic analysis and practical measurement prove that employing moderate thick and low loss substrate helps to enhance the impedance bandwidth and efficiency of the microstrip antenna for size reduction