A defective ground technique for reducing crosstalk induced by on-chip antennas in RFIC environment

Abstract

Abstract Crosstalk is induced due to the on-chip antenna (OCA) in RFIC, which affects nearby RFIC blocks, degrading signal integrity and overall system performance. In this work, a defected ground structure (DGS) based technique with a meandered loop OCA is proposed to reduce crosstalk at a frequency of 10.3 GHz. The DGS is introduced between the silicon substrate and the top metal layer meandered loop OCA, separated by a thick $$SiO_2$$ layer, which effectively reduces the crosstalk. Moreover, to make the study suitable for compact ICs, crosstalk analysis is performed by keeping the blocks at various positions with respect to the reference antenna separated at $$d = 6$$ mm with orientations of $$0^\circ$$ , $$45^\circ$$ , and $$90^\circ$$ with respect to the x-axis. The obtained $$S_{12}$$ values reach up to $$-85$$ dB, $$-91$$ dB, and $$-77$$  dB, respectively. Furthermore, an extensive parametric analysis is performed to justify the design considerations and optimum values of the parameters. To examine the crosstalk behaviour of the proposed OCA, an equivalent circuit model analysis is performed. The characterization is validated using a fabricated prototype. The results demonstrate that the proposed multi technique based multi-path suppression of electromagnetic coupling method provides ultra-high isolation, compact size, and an improved figure of merit for minimizing crosstalk in highly integrated RFIC environments.