A compact integrated antenna-mixer using microstrip circular patch at 2.4 GHz

This paper proposes design of a compact integrated antenna-mixer using a microstrip circular patch resonator at 2.4 GHz. The antenna in the structure is a circular microstrip patch antenna. In the mixer design, the field configurations of TM11 resonant mode of the microstrip circular patch resonator are utilized to achieve good RF-to-IF and LO-to-IF isolation without using an IF filter. The mixer uses Schottky barrier diode for mixing purpose and exhibits minimum isotropic conversion loss of 10.73 dB and greater than 17 dB of LO-to-IF and RF-to-IF isolations for 3 dB RF bandwidth of 100 MHz. The integrated antenna-mixer can be used in low power, low cost short range microwave communications and sensor design.