Miniaturized (127 to 154) GHz Dipole Arrays in 28 nm Bulk CMOS With Enhanced Efficiency

Abstract

This article presents the design of integrated antennas in the <inline-formula> <tex-math notation= LaTeX >$D$ </tex-math></inline-formula>-band (110–170 GHz). First, an electromagnetic analysis is used to tune the propagation characteristics of surface waves supported on an artificial magnetic conductor (AMC). Next, a subarray of two miniaturized dipoles is designed where each dipole attains axial resonance and the separation between them is optimized for substrate wave cancellation. This subarray simultaneously performs spatial power combining and substrate wave cancellation, leading to significant increase of the effective isotropic radiated power (EIRP). Two miniaturized dipoles with axial length of <inline-formula> <tex-math notation= LaTeX >$252~\\mu \\text{m}$ </tex-math></inline-formula> and spacing of <inline-formula> <tex-math notation= LaTeX >$450~\\mu \\text{m}$ </tex-math></inline-formula> was fabricated in 28 nm bulk CMOS with low resistivity silicon (<inline-formula> <tex-math notation= LaTeX >$10~\\Omega \\cdot $ </tex-math></inline-formula>cm). Each dipole is fed by a cascade of two triplers and a power amplifier. Measurements show a gain of 2.3 dBi, EIRP of 12.2 dBm at 139 GHz and a 3 dB bandwidth of 127–154 GHz (19% fractional) without using any additional substrates, lenses, or postprocessing steps. Scalability of this technique for forming larger arrays is also presented.